"A mouth," said Conway, "with muscles to open and close it, with teeth, predigestive juices and an alimentary canal joining it to a stomach which, unless it decided to form that as well, could be many miles away- all within a few minutes of the ship landing? From what we know of carpet metabolism I can't see all that happening so quickly, can you?"

            Edwards and Harrison were silent.

            "From our study of the carpet inhabiting that small island to the north," said Conway, "we have a fair idea of how they function."

            Since the day after their arrival the island had been kept under constant observation. Its inhabitant had an incredibly slow, almost vegetable, metabolism. The carpet's upper surface appeared not to move, but it did in fact alter its contours so as to provide a supply of rainwater wherever needed for the plant life which recycled its air and wastes or served as an additional food supply. The only real activity occurred around the fringes of the carpet, where the great being had its mouths. But here again it was not the carpet itself which moved quickly but the hordes of predators who tried to eat it while it slowly and ponderously ate them in with the thick, food-rich sea water. The other big carpets unlucky enough not to have a fringe adjoining the sea ate vegetation and each other.

            The carpets did not possess hands or tentacles or manipulatory appendages of any kind-just mouths and eyes capable of tracking an arriving spaceship.

            "Eyes?" said Edwards. "Why didn't they see our scout ship?"

            "There have been dozens of scout ships and copters flitting about recently," said Conway, "and the beast may be confused. But what I'd like you to do now, Lieutenant, is take your ship up to, say, one thousand feet and do a series of figure-eight turns. Do them as tightly and quickly as possible, cover the same area of ground each time and make the crossover point directly above our heads. Got it?"

            "Yes, but . .

            "This will let the beastie know that we aren't just any scout ship but a very special one," Conway explained, then added, "be ready to pick us up in a hurry if something goes wrong.

            A few minutes later Harrison took off, leaving the two doctors standing beside their drilling rig. Edwards said, "I see what you mean, Doctor. You want to attract attention to us. 'X' marks the spot and an 'X' with closed ends is a figure-eight. Persistency of vision will do the rest."

            The scout ship was criss-crossing above them in the tightest turns Conway had ever seen. Even with the ship's gravity compensators working at full capacity Harrison must have been taking at least four Gs. On the ground the ship's shadow whipped past and around them, trailing a long, bright yellow line of rolled-up leaves. The ground shook to the thunder of the tiny vessel's jet and then, very slightly, it began shaking by itself.

"Harrison!"

            The scout ship broke off the maneuver and roared into a landing behind them. By then the ground was already beginning to sag.

            Suddenly they appeared.

            Two large, flat metal disks embedded vertically in the ground, one about twenty feet in front of them and the other the same distance behind. As they watched each disk contracted suddenly into a shapeless blob of metal which crawled a few feet to the side and then suddenly became a large, razor-edged disk again, cutting a deep incision in the ground. The disks had each cut more than a quarter circle around them and the ground was sagging rapidly inside the incisions before Conway realized what was happening.

            "Think cubes at them!" he yelled. "Think something blunt! Harrison!"

            "Lock's open. Come running."

            But they could not run without taking their eyes and minds off the disks, and if they did that they could not run fast enough to clear the circular incision which was being made around them. Instead they sidled toward the scout ship, willing every inch of the way that the disks become cubes or spheres or horseshoes-anything but the great, circular scalpels which something had made them become.

At Sector General Conway had watched his colleague Mannon perform incredible feats of surgery, using one of these thought-controlled tools, an all-purpose surgical instrument which became anything he wanted it to be instantly. Now two of the things were crawling and twisting like metallic nightmares as they tried to shape them one way and something else-which was their owner and as such had more expertise-tried to shape them another. It was a very one-sided struggle but they did, just barely, manage to hamper their opponent's thinking enough to allow them to get clear before the circular plug of "skin" containing the drilling rig and other odds and ends of equipment dropped from sight.

            "They're welcome to it," said Major Edwards as the lock slammed shut and Harrison lifted off. "After all, we've been taking specimens for weeks and it may give them something to think about before we broaden contact with shadow diagrams." He grew suddenly excited as he went on, "With high-acceleration radio-controlled missiles we can build up quite complex figures!"

            Conway said, "I was thinking more in terms of a tight beam of light projected onto the surface at night. The leaves should react by opening and the beam could be moved very quickly in a rectangular sweep pattern like old-fashioned TV. It might even be possible to project moving pictures."

            "That's it," said Edwards enthusiastically. "But how a dirty great beast the size of a county, who doesn't have arms, legs or anything else, will be able to answer our signals is another matter. Probably it will think of something."

            Conway shook his head. "It is possible that despite their slow movements the carpets are capable of quick thinking, that they are in fact the tool users we are looking for and that their enormous bodies undergo voluntary surgery whenever they want to draw in and examine a specimen which is not within reach of a mouth. But I prefer the theory of a smaller, intelligent life-form inside or under the big one, an intelligent parasite perhaps which helps maintain the host in good health by the use of the tools and other abilities, and which makes use of the host being's 'eyes' as well as everything else. You can take your pick."

            There was silence while the scout ship leveled off on a course which would take it back to the mother ship, then Harrison said, "We haven't made direct contact, then-we've just put squiggles on a vegetable radar screen? But it is still a big step forward."

            "As I see it," said Conway, "if tools were being used to bring us to them, they must be a fair distance from the surface-perhaps they can't exist on the surface. And don't forget they would use the carpet exactly as we use vegetable and mineral resources. How would they analyze life samples? Would they be able to see them at all down there? They use plants for eyes but I can't imagine a vegetable microscope. Perhaps they would use the big beastie's digestive juices in certain stages of the analysis .

            Harrison was beginning to look a little green around the gills. He said, "Let's send down a robot sensor first, to see what they do, eh?"

            Conway began, "This is all theory. .

            He broke off as the ship's radio hummed, cleared its throat and said

briskly, "Scout ship Nine. Mother here. I have an urgent signal for Doctor

Conway. The being Camsaug has gone on vacation wearing the tracer the

Doctor gave it. It is heading for the active stretch of shore in area

H-Twelve. Harrison, have you anything to report?"

            "Yes, indeed," replied the Lieutenant, glancing at Conway. "But first I think the Doctor wants to speak to you."

            Conway spoke briefly and a few minutes later the scout ship leaped ahead under emergency thrust, ripping through the sky too fast for even the leaves to react to its shadow and trailing an unending shock wave which would have deafened anything on the surface with ears to hear. But the great carpet slipping past them might well number deafness among its many other infirmities which now, Conway thought angrily, included a number of well-developed and extensive skin cancers and God alone knew what else.

            He wondered if a great, slow-moving creature like this could feel pain, and if so, how much? Was the condition he could see confined to hundreds of acres of "skin" or did it go much deeper? What would happen to the beings living in or under it if too many of the carpets died, decomposed? Even the rollers with their offshore culture would be affected-the ecology of the whole planet would be wrecked! Somebody was going to have to talk to the rollers, politely but very, very firmly, if it wasn't already too late.

            All at once the horse-trading aspect of his assignment, the swapping of tools for medical assistance, was no longer important. Conway was beginning to think like a doctor again, a doctor with a desperately ill patient.

            At Descartes the copter he had requested was waiting. Conway changed into a lightweight suit with a propulsion motor strapped onto his back and extra air tanks on his chest. Camsaug had too great a lead for him to follow on foot, so Conway would fly out to the being's present position by helicopter. Harrison was at the controls.

            "You again," said Edwards.

            The Lieutenant smiled. "This is where the action is. Hold tight."

            After the mad dash to the mother ship the helicopter trip seemed incredibly slow. Conway felt that he would fall flat on his face if it did not speed up and Edwards assured him that the feeling was mutual and that they would have made better time swimming. They watched Camsaug's trace grow larger in the search screen while Harrison cursed the birds and flying lizards diving for fish and suiciding on his rotor blades.

            They flew low over the settled stretch of coast where the shallows were protected from the large predators of the sea by a string of offshore islands and reefs. To this natural protection the rollers had added a landward barrier of dead land-beast by detonating a series of low-power nuclear devices inside the vast creature's body. The area was now so settled that doughnuts could roll with very little danger far inside the beast's cavernous mouths and prestomachs and out again.

            But Camsaug was ignoring the safe area. It was rolling steadily toward the gap in the reef leading to the active stretch of coast where predators large, medium and small ate and eroded the living shore.

            "Put me down on the other side of the gap," said Conway. "I'll wait until Camsaug comes through, then follow it."

            Harrison brought the copter down to a gentle landing on the spot indicated and Conway lowered himself onto a float. With his visor open and his head and shoulders projecting through the floor hatch he could see both the search screen and the half-mile distant shore. Something which looked like a flatfish grown to the dimensions of a whale hurled itself out of the water and flopped back again with a sound like an explosion. The wave reached them a few seconds later and tossed the copter about like a cork.

            "Frankly, Doctor," said Edwards, "I don't understand why you're doing this. Is it scientific curiosity regarding roller mating habits? A yen to look into the gaping gullet of a land beast? We have remote-controlled instruments which will let you do both without danger once we get a chance to set them up..

            Conway said, "I'm not a peeping Tom, scientific or otherwise, and your gadgetry might not tell me what I want to know. You see, I don't know what exactly I'm looking for, but I'm pretty sure that this is where I can contact them-"

            "The tool users? But we can contact them visually, through the plants."

            "That may be more difficult than we expect," Conway said. "I hate to attack my own lovely theory, but let's say that because of their vegetable vision they have difficulty in grasping concepts like astronomy and space travel or, as beings who live in or under their enormous host, of visualizing it from an outside viewpoint..

            This was just another theory, Conway went onto explain, but the way he saw it the tool users had gained a large measure of control over their environment. On a normal world environmental control included such items as reforestation, protection against soil erosion, efficient utilization of natural resources and so on. Perhaps on this world these things were not the concern of geologists and farmers but of people who, because their environment was a living organism, were specialists in keeping it healthy.

            He was fairly sure that these beings would be found in peripheral areas where the giant organism was under constant attack and in need of their assistance. He was also sure that they would do the work themselves rather than use their tools because these thought-controlled devices had the disadvantage of obeying and shaping themselves to the nearest thought source-this had been proved many times at the Hospital as well as earlier today. Probably the tools were valuable, too much so to risk them being swallowed and/or rendered useless by the savage and disorganized thinking of predators.

            Conway did not know what these people called themselves-the rollers called them Protectors or Healers or an almost certain method of committing suicide because they killed more often than they cured. But then the most famous Tralthan surgeon in the Federation would probably kill an Earth-human patient if it had no medical knowledge of the species and no physiology tape available. The tool users worked under a similar handicap when they tried to treat rollers.

            "But the important thing is they do try," Conway went on. "All their efforts go toward keeping one big patient alive instead of many. They are the medical profession on Meatball and they are the people we must contact first!"

            There was silence then except for the gargantuan splashing and smacking sounds coming from the shoreline. Suddenly Harrison spoke.

            "Camsaug is directly below, Doctor."

            Conway nodded, closed his visor and fell awkwardly into the water. The weight of his suit's propulsor and extra air tanks made him sink quickly and in a few minutes he spotted Camsaug rolling along the sea bottom. Conway followed, matching the roller's speed and keeping just barely in sight. He had no intention of invading anyone's privacy. He was a doctor rather than an anthropologist and he was interested in seeing what Camsaug did only if it ran into trouble of a medical nature.

            The copter had taken to the air again, keeping pace with him and maintaining constant radio contact.

            Camsaug was angling gradually toward the shore, wobbling past clumps of sea vines and porcupine carpets which grew more thickly as the bottom shelved, sometimes circling for several minutes while one of the big predators drifted across its path. The vines and prickly carpets had poisonous thorns and quills and they lashed out or shot spines at anything which came too close. Conway's problem now was how to drift past them at a safe altitude but remain low enough so as not to be scooped up by a giant flatfish.

            The water was becoming so crowded with life and animal and vegetable activity that he could no longer see the surface disturbance caused by the helicopter. Like a dark-red precipice the edge of the land beast loomed closer, almost obscured by its mass of underwater attackers, parasites and, possibly, defenders-the situation was too chaotic for Conway to tell which was which. He began to encounter new forms of life aglistening black and seemingly endless mass which undulated across his path and tried to wrap itself around his legs and a great, iridescent jellyfish so transparent that only its internal organs were visible.

            One of the creatures had spread itself over about twenty square yards of seabed while another drifted just above it. They did not carry spines or stings so far as he could see, but everything else seemed to avoid them and so did Conway.

            Suddenly Camsaug was in trouble.

            Conway had not seen it happen, only that the roller had been wobbling more than usual and when he jetted closer he saw a group of poisoned quills sticking out of its side. By the time he reached it Camsaug was rolling in a tight circle, almost flat against the ground, like a coin in slow motion that has almost stopped spinning. Conway knew what to do, having dealt with a similar emergency when Surreshun was being transferred into the Hospital. He quickly lifted the roller upright and began pushing it along the bottom like an oversize, flabby hoop.

            Camsaug was making noises which did not translate, but he felt its body grow less flabby as he rolled it-it was beginning to help itself. Suddenly it wobbled away from him, rolling between two clumps of sea vines. Conway rose to a safe height meaning to head it off, but a flatfish with jaws gaping rushed at him and he dived instinctively to avoid it.

            The giant tail flicked past, missing him but tearing the propulsion unit from his back. Simultaneously a vine lashed out at his legs, tearing the suit fabric in a dozen places. He felt cold water forcing its way up his legs and under the skin something which felt like liquid fire pushing along his veins. He had a glimpse of Camsaug rolling like a stupid fool onto the edge of a jellyfish and another of the creatures was drifting down on him like an iridescent cloud. Like Camsaug, the noises he was making were not translatable.

            "Doctor!" The voice was so harsh with urgency that he could not recognize it. "What's happening?"

            Conway did not know and could not speak anyway. As a precaution against damage in space or in a noxious atmosphere his suit lining was built in annular sections which sealed off the ruptured area by expanding tightly against the skin. The idea had been to contain the pressure drop or gas contamination in the area of damage, but in this instance the expanded rings were acting as a tourniquet which slowed the progress of the poison into his system. Despite this Conway could not move his arms, legs or even his jaw. His mouth was locked open and he was able-just barely able-to breathe.

            The jellyfish was directly above him. It edges curled down over his body and tightened, wrapping him in a nearly invisible cocoon.

            "Doctor! I'm coming down!" It sounded like Edwards.

            He felt something stab several times at his legs and discovered that the jellyfish had spines or stings after all and was using them where the fabric of his suit had been torn away by the vines. Compared with the burning sensation in his legs the pain was relatively slight, but it worried him because the jabs seemed very close to the popliteal arteries and veins. With a tremendous effort he moved his head to see what was happening, but by then he already knew. His transparent cocoon was turning bright red.

            "Doctor! Where are you? I can see Camsaug rolling along. Looks like it's wrapped up in a pink plastic bag. There's a big, red ball of something just above it-"

            "That's me..." began Conway weakly.

            The scarlet curtain around him brightened momentarily. Something big and dark flashed past and Conway felt himself spinning end over end. The redness around him was becoming less opaque.

            "Flatfish," said Edwards. "I chased it with my laser. Doctor?"

            Conway could see the Major now. Edwards wore a heavy-duty suit which protected him from vines and quills but made accurate shooting difficult-his weapon seemed to be pointing directly ~t Conway. Instinctively he put up his hands and found that his arms moved easily. He was able to turn his head, bend his back and his legs were less painful. When he looked at them the area of his knees was bright red but the body around it seemed more rather than less transparent.

            Which was ridiculous!

            He looked at Edwards again and then at the awkward, dangerously slow rolling of the wrapped-up Camsaug. A great light dawned.

            "Don't shoot, Major," said Conway wealdy but distinctly. "Ask the Lieutenant to drop the rescue net. Winch both of us up to the copter and to Descartes, fast. Unless our friend here can't survive in air, of course. In that case haul us both to Descartes submerged-my air will last. But be very careful not to hurt it."

            They both wanted to know what the blazes he was talking about. He did his best to explain, adding, "So you see, not only is it my opposite number, the Meatball equivalent of a doctor, but I owe it my life as well. There is a close, personal bond between us-you might almost say that we were blood brothers."

MEATBALL

Conway had been worrying about the Meatball problem during the whole of the trip back to the hospital, but only in the past two hours had the process become a constructive one. That had been the period during which he had finally admitted to himself that he could not solve the problem and had begun thinking of the names and professional capabilities of some of the beings, human and otherwise, who might help him find the solution. He was worrying so hard and constructively that he did not know that their ship had materialized the regulation twenty miles from the hospital until the flat, translated voice of Reception rattled from the control room's speaker.

            "Identify yourself please. Patient, visitor, or staff and species."

            The Corps lieutenant who was piloting looked back at Conway and Edwards, the mother ship's medical officer and raised an eyebrow.

            Edwards cleared his throat nervously and said, "This is scout ship Dl 835, tender and communications ship to the Monitor Corps survey and cultural contact vessel Descartes. We have four visitors and one staff member onboard. Three are human and two are native Drambons of different-"

            "Give physiological classifications, please, or make full-vision contact. All intelligent races refer to themselves as human and consider others to be nonhuman, so what you call yourself is irrelevant so far as preparing or directing you to suitable accommodation is concerned."

            Edwards muted the speaker and said helplessly to Conway, "I know what we are, but how the blazes do I describe Surreshun and the other character to this medical bureaucrat?"

            Thumbing the transit switch, Conway said, "This ship contains three Earth-humans of physiological classification DBDG. They are Major Edwards and Lieutenant Harrison of the Monitor Corps and myself, Senior Physician Conway. We are carrying two Drambon natives. Drambo is the native name for the planet-you may still have it listed as Meatball, which was our name for it before we knew it had intelligent life. One of the natives is a CLHG, water-breathing with a warm-blooded oxygen-based metabolism. The other is tentatively classified as SRJH and seems comfortable in either air or water.

            "There is no urgency about the transfer," Conway went on. "At the same time the CLHG occupies a physically irksome life-support mechanism and would doubtless feel more comfortable in one of our water filled levels where it can roll normally. Can you take us at lock Twenty-three or Twenty-four?"

            "Lock Twenty-three, Doctor. Do the visitors require special transport or protective devices for the transfer?"

            "Negative."

            "Very well. Please inform Dietetics regarding food and liquid requirements and the periodicity of their meals. Your arrival has been notified and Colonel Skempton would like to see Major Edwards and Lieutenant Harrison as soon as possible. Major O'Mara would like to see Doctor Conway sooner than that."

            "Thank you."

            Conway's words were received by the being who was manning the reception board, whose translator pack relayed them to the computer which occupied three whole levels at the nerve-center of the hospital, which in turn returned them stripped of all emotional overtones to the scaly, furry, or feathery receptionist in the form of hoots, cheeps, growls, or whatever other odd noises the being used as its spoken language.

            To Edwards, Conway said, "Unless you are attached to a multienvironment hospital you normally meet e-ts one species at a time and refer to them by their planet of origin. But here, where rapid and accurate knowledge of incoming patients is vital, because all too often they are in no condition to furnish this information themselves, we have evolved the four-letter classification system. Very briefly, it works like this.

            "The first letter denotes the level of physical evolution," he continued. "The second indicates the type and distribution of limbs and sense organs and the other two the combination of metabolism and gravity-pressure requirements, which in turn gives an indication of the physical mass and form of tegument possessed by a being. Usually we have to remind some of our e-t students at this point that the initial letter of their classification should not be allowed to give them feelings of inferiority, and that the level of physical evolution has no relation to the level of intelligence."

            Species with the prefix A, B and C, he went onto explain, were water breathers. On most worlds life had begun in the seas and these beings had developed high intelligence without having to leave it. D through F were warm-blooded oxygen breathers, into which group fell most of the intelligent races in the galaxy, and the G to K types were also oxygen breathing but insectile. The Ls and Ms were light-gravity, winged beings.

            Chlorine-breathing life-forms were contained in the 0 and P groups, and after that came the more exotic, the more highly evolved physically and the downright weird types. Radiation eaters, frigid-blooded or crystalline beings and entities capable of modifying their physical structure at will. Those possessing extrasensory powers sufficiently well-developed to make walking or manipulatory appendages unnecessary were given the prefix V regardless of size or shape.

            "There are anomalies in the system," Conway went on, "but those can be blamed on a lack of imagination by its originators-the AACP life-form, for instance, which has a vegetable metabolism. Normally the prefix A denotes a water breather, there being nothing lower in the system than the piscatorial life-forms, but the AACPs are intelligent vegetables and plants came before fish-"

            "Sorry, Doctor," said the pilot. "We'll be docking in five minutes and you did say that you wanted to prepare the visitors for transfer."

            Conway nodded and Edwards said, "I'll lend a hand, Doctor."

            The scout ship entered the enormous cubic cavern which was Lock Twenty-three while they were donning the lightweight suits used for environments where the liquid or gas was lethal but at reasonably normal pressures. They felt the grapples draw them into the adjustable cradle and staggered slightly as the artificial gravity grids were switched on. The Lock's outer seal clanged shut and there was the sound of waterfalls pouring down metal cliffs.

            Conway had just finished securing his helmet when its receiver said, "Harrison here, Doctor. The reception team leader says that it will take some time to completely fill the lock with water as well as making it necessary to carry out the full anti contamination procedure at the other five internal entrances. It is a big lock, pressure of water on the other seals will be severe

if-"

            "Filling won't be necessary," said Conway. "The Drambon CLCH will be all right so long as the water reaches the top edge of the freight hatch."

            "The man says bless you."

            They let themselves into the scout ship's hold, carefully avoiding the self-powered life support machinery which kept the first Drambon rotating like an organic prayer wheel as they removed the retaining straps from the freight lashing points.

            "We've arrived, Surreshun," said Conway. "In a few minutes you'll be able to say good-bye to that contraption for a few days. How is our friend?"

            It was a purely rhetorical question because the second Drambon did not and perhaps could not speak. But if it could not converse it could at least react. Like a great, translucent jellyfish-it would have been completely invisible in water had it not been for its iridescent skin and a few misty internal organs-the Drambon undulated toward them. It curled around Conway like a thick, translucent cocoon for a moment, then transferred its attentions to Edwards.

            "Ready when you are, Doctors."

            "This is a much better entrance than your first one," said Conway as Edwards helped him maneuver Surreshun's life-support equipment out of the hold. "At least this time we know what we are doing."

            "There is no need to apologize, friend Conway," said Surreshun in its flat, translated voice. "To a being of my high intelligence and ethical values, sympathy for the mental shortcomings of lesser beings and, of course, forgiveness for any wrongs they may have done me are but small facets of my generous personality."

            Conway had not been aware that he was apologizing, but to a being to whom the concept of modesty was completely alien it was possible that his words had sounded that way. Diplomatically he said nothing.

Lock Twenty-three's reception team arrived to help them move Surreshun's wheel to the entrance to the water-filled AUGL wards. The team leader, whose black suit had red and yellow striped arms and legs making him look like an updated court jester, swam up to Conway and touched helmets.

            "Sorry about this, Doctor," his voice sounded, clearly if somewhat distorted by the transmitting media, "but an emergency has come up suddenly and I don't want to tie up the suit frequency. I'd like all you people to move into the ward as quickly as possible. Surreshun has been through our hands before so we don't have to worry about it, just take charge of the other character wherever it is and. . . What the blazes!"

            The other character had wrapped itself around his head and shoulders, pinioning his arms and nuzzling at him like a dog with a dozen invisible heads.

            "Maybe it likes you," said Conway. "If you ignore it for a minute it will go away.

            "Things usually do find me irresistible," said the team leader dryly. "I wish the same could be said for females of my own species..

            Conway swam around and over it, grabbed two large handfuls of the flexible, transparent tegument covering its back and kicked sideways against the water until the being's front end was pointing toward the ward entrance. Great, slow ripples moved along its body and it began undulating toward the corridor leading to the AUGL ward like an iridescent flying carpet. Less gracefully Surreshun's ferris wheel followed close behind.

            "An emergency, you said?"

            "Yes, Doctor," said the team leader on the suit frequency. "But nothing will happen for another ten minutes, so I can use the suit radio if we keep it brief. My information is that a Kelgian DBLF on the Hudlar operating theater staff was injured by a muscular spasm and involuntary movement of the patient's forward tentacles during the course of the op. The injuries are complicated by compression effects plus the fact that the constituents of that high-pressure muck which Hudlars breathe are highly toxic to the Kelgian metabolism. But it is the bleeding which is the real cause of the emergency. You know Kelgians."

            "Yes, indeed," said Conway.

            Even a small punctured or incised wound was a very serious matter for a Kelgian. They were giant, furry caterpillars and only their brain, which was housed in the blunt, conical head section, was protected by anything resembling a bony structure. The body consisted of a series of wide, circular bands of muscle which gave it mobility and served to protect, very inadequately, the vital organs within.

            The trouble was that to give those tremendous bands of muscle an adequate blood supply the Kelgian pulse rate and pressure were, by Earth standards, abnormally high.

            "They haven't been able to control the bleeding very well," the team leader went on, "so they are moving it from the Hudlar section two levels above us to the Kelgian theater just below, and taking it through the water-filled levels to save time. . . Excuse me, Doctor, here they come.

            Several things happened at once just then. With an untranslatable gurgle of pleasure Surreshun released itself from the wheel and went rolling ponderously along the floor, zig-zagging slowly among the patients and nursing staff who ranged from squat, crab-like Melfans to the forty foot long tentacled crocodile who were natives of the ocean-covered world of Chalderescol. The other Drambon had twitched itself free of Conway's grip and was drifting away, while high up on the opposite wall a seal had opened and the injured Kelgian was being moved in, attended by too many people for Conway's assistance to be either necessary or desirable.

            There were five Earth-humans wearing lightweight suits like his own, two Kelgians, and an Illensan whose transparent envelope showed the cloudy yellow of chlorine inside. One of the Earth-human helmets contained a head which he recognized, that of his friend Mannon who specialized in Hudlar surgery. They swarmed around the Kelgian casualty like a shoal of ungainly fish, pushing and tugging it toward the other side of the ward, the size of the shoal increasing as the reception-team leader and his men swam closer to assess the situation. The Drambon jellyfish also moved closer.

            At first Conway thought the being was merely curious, but then he saw that the carpet of iridescence was undulating toward the injured being with intent.

            "Stop it!" Conway shouted.

            They all heard him because he saw them jerk as his voice rattled deafeningly from their suit phones. But they did not know and there was no time to tell them who, what, or even how to stop it.

            Cursing the inertia of the water Conway swam furiously toward the injured Kelgian, trying to head the Drambon off. But the big, blood soaked area of fur on the Kelgian's side was drawing the other like a magnet and, like a magnet, its attraction increased with the inverse square of the distance. Conway did not have time to shout a warning before the Drambon struck softly and clung.

            There was a soft explosion of bubbles as the Drambon's probes ruptured the Kelgian's pressure litter and slid into the already damaged suit it had been wearing in the Hudlar theater and through the thick, silvery fur beneath. Within seconds its transparent body was turning a deepening shade of red as it sucked the blood from the injured Kelgian.

            "Quickly," Conway yelled, "get them both to the air-filled section!"

            He could have saved his breath because everyone was talking and overloading the suit radio. The direct sound pickup was no help, either- all he could hear was the deep, water-borne growl of the ward's emergency siren and too many voices jabbering at once, until one very loud, translated Chalder voice roared out above the others.

            "Animal! Animal!"

            His strenuous swimming had overloaded the drying elements in his suit, but those words caused the sweat bathing his body to turn from hot to cold.

            Not all the inhabitants of Sector General were vegetarians by any means, and their dietary requirements necessitated vast quantities of meat from extraterrestrial as well as terrestrial sources to be shipped in. But the meat invariably arrived frozen or otherwise preserved, and for a very good reason. This was to avoid cases of mistaken identity on the part of the larger, meat-eating life-forms who very often came into contact with smaller e-ts who frequently bore a physical resemblance to the former's favorite food.

            The rule in Sector General was that if a being was alive, no matter what size or shape it might take, then it was intelligent.

            Exceptions to this rule were very rare and included pets-nonviolent, of course-belonging to the staff or important visitors. When a nonintelligent being entered the hospital by accident, protective measures had to be taken very quickly if the smaller intelligent life-forms were not to suffer.

            Neither the medical staff engaged in transferring the casualty nor the reception team were armed, but in a few minutes' time the alarm siren would bring corpsmen who would be and meanwhile one of the Chalder patients-all multitentacled, armored, thirty feet of it-was moving in to remove the clinging Drambon with one or at most two bites of its enormous jaws.

            "Edwards! Mannon! Help me keep it off!" Conway shouted, but there were still too many other people shouting for them to hear him. He grabbed two fistfuls of the Drambon's tegument and looked around wildly. The team leader had reached the scene at the same time and he had pushed one leg between the injured Kelgian and the clinging SRJH and with his hands was trying to pry them apart. Conway twisted around, drew both knees up to his chin and with both feet booted the team leader clear. He could apologize later. The Chalder was moving dangerously close.

            Edwards arrived then, saw what Conway was doing and joined him.

Together they kicked out at the gigantic snout of the Chalder, trying to drive it away. They could not hurt the brute, but were trusting the e-t not to attack two intelligent beings in order to kill an apparent animal who was attacking a third intelligent being. The situation was sufficiently confused, however, for a mistake to be made. It was quite possible that Edwards and Conway could have their legs amputated from the waist down.

            Suddenly Conway's foot was grabbed by a pair of large, strong hands and his friend Mannon swarmed along his body until their helmets were touching.

            "Conway, what the blazes are you...

            "There's no time to explain," he replied. "Just get them both to the air-filled section quickly. Don't let anyone hurt the SRJH, it isn't doing any harm.

            Mannon looked at the being who was covering the Kelgian like an enormous, blood-red blister. No longer transparent, the blood of the injured nurse could actually be seen entering and being diffused throughout the Drambon's great, slug-like body which now seemed filled to bursting point.

            "You could have fooled me," said Mannon, and pulled away. With one hand he gripped one of the Chalder's enormous teeth, swung around until he was staring it in an eye nearly the size of a football and with his other hand made jabbing, sideways motions. Looking confused the Chalder drifted away, and a few seconds later they were in the lock leading to the air-filled section.

            The water drained out and the seal opened to show two green-clad Corpsmen standing in the lock antechamber, weapons at the ready. One of them cradled an enormous gun with multiple magazines capable of instantly anesthetizing any one of a dozen or more life-forms who came within the category of warm-blooded oxygen breathers, while the other held a tiny and much less ferocious-looking weapon which could blast the life from a bull elephant or any e-t equivalent.

            "Hold it!" said Conway, slipping and skidding across the still-wet floor to stand in front of the Drambon. "This is a VIP visitor. Give us a few minutes. Everything will be all right, believe me.

            They did not lower their weapons, neither did they look as though they believed him.

            "You'd better explain," said the team leader quietly, but with the anger showing in his face.

            "Yes," said Conway. "I, ah, hope you weren't hurt when I kicked you back there."

            "Only my dignity, but I still-"

            "O'Mara here," roared a voice from the communicator on the wall opposite. "I want vision contact. What's happening down there?"

            Edwards was closest. He trained and focused the vision pickup as directed and said, "The situation is rather complicated, Major-"

            "Naturally, if Conway has anything to do with it," said O'Mara caustically. "What is he doing there, praying for deliverance?"

            Conway was on his knees beside the injured Kelgian, checking on its condition. From what he could see the Drambon had attacked itself so tightly that very little water had entered the pressure litter or the damaged protective suit-it was breathing normally with no indications of water in its lungs. The Drambon's color had lightened again. No longer deep red, it had returned to its normal translucent iridescent coloring tinged only faintly with pink. As Conway watched, it detached itself from the Kelgian and rolled like a great, water-filled balloon to come to rest against the wall.

            Edwards was saying ..... A full report on this life-form three days ago. I realize three days is not a long time for the results to be disseminated throughout an establishment of this size, but none of this would have happened if the Drambon had not been exposed to a seriously injured being who-"

            "With respect, Major," said O'Mara in a voice oozing with everything else but, "a hospital is a place where anyone at any time can expect to see serious illness or injury. Stop making excuses and tell me what happened!"

            "The Drambon over there," put in the team leader, "attacked the injured Kelgian."

            "And?" said O'Mara.

            "Cured it instantly," said Edwards smugly.

            It was not often that O'Mara was lost for words. Conway moved to one side to allow the Kelgian, who was no longer a casualty, to climb to its multitudinous feet. He said, "The Drambon SRJH is the closest thing to a doctor that we have found on that planet. It is a leech-like form of life which practices its profession by withdrawing the blood of its patients and purifying it of any infection or toxic substances before returning it to the patient's body, and it repairs simple physical damage as well. Its reaction in the presence of severe illness or injury is instinctive. When the injured Kelgian appeared suddenly it wanted to help. The casualty was suffering from poisoning due to toxic material from the Hudlar theater environment infecting the wound. So far as the Drambon was concerned it was a very simple case.

            "Not all the blood withdrawn is returned, however," Conway went on, 'and we have not been able to establish whether it is physiologically impossible for the being to return all of it or whether it retains a few ounces as payment for services rendered."

            The Kelgian gave a low-pitched hoot like the sound of a modulated foghorn. The noise translated as "It's very welcome, I'm sure."

            The DBLF moved away then followed by the two armed corpsmen. With a baffled look at the Drambon the team leader waved his men back to their stations and the silence began to drag.

            Finally O'Mara said, "When you've taken care of your visitors and if there are no physiological reasons against it, I suggest we meet to discuss this. My office in three hours."

            His tone was ominously mild. It might be a good idea if Conway roped in some moral as well as medical support for the meeting with the Chief Psychologist.

Conway asked his empath friend Prilicla to attend the meeting as well as the Monitor officers Colonel Skempton and Major Edwards, Doctor Mannon, the two Drambons, Thornnastor, the Diagnostician-in-Charge of Pathology, and two medics from Hudlar and Melf who were currently taking courses at the hospital. It took several minutes for them all to enter O'Mara's enormous outer office-a room normally occupied only by the Major's aide and more than a score of pieces of furniture suited to the e-ts with whom O'Mara had professional contact. On this occasion it was the Chief Psychologist who occupied his assistant's desk and waited with visibly controlled impatience for everyone to sit, lie, or otherwise insinuate themselves into the furniture.

            When they had done so O'Mara said quietly, "Since the period of high drama accompanying your arrival, I have caught up with the latest Meatball reports, and to know all is to forgive all-except, of course, your presence here, Conway. You were not due back for another three-"

            "Drambo, sir," said Conway. "We use the native word sound for it now.

            "We prefer that," Surreshun's translated voice joined in. "Meatball is not an accurate name for a world covered with a relatively thin layer of animal life, or for what we consider to be the most beautiful planet in the galaxy-even though we have not as yet had an opportunity to visit any of the others. Besides, your translator tells me that Meatball as a name lacks accuracy, reverence and respect. The continued use of your name for our glorious planet will not anger me-I have too great an understanding of the often shallow thinking engaged in by your species, too much sympathy for these mental shortcomings to feel anger or even irritation-"

            "You're too kind," said O'Mara.

            "That as well," agreed Surreshun.

            "The reason I returned," Conway said hastily, "was simply to get help. I wasn't making any progress with the Drambo problem and it was worrying me."

            "Worry," said O'Mara, "is a particularly useless activity-unless, of course, you do it out loud and in company. Ah, now I see why you brought half the hospital along."

            Conway nodded and went on, "Drambo is badly in need of medical assistance, but the problem is unlike any other that we have already met on Earth-human or e-t planets and colonies. On those occasions it was simply a matter of investigating and isolating the diseases, bringing in or suggesting where the specifics could be distributed most effectively and then allowing the people affected to administer their own medicine through local doctors and facilities. Drambo is not like that. Instead of trying to diagnose and treat a large number of individuals, the patients are relatively few but very, very large indeed.

            "The reason for this is that within the past few years Surreshun's race has learned how to liberate atomic energy," Conway went on, then added, "Explosively, of course, and with vast quantities of radiational dirt. They are very.. ." he hesitated, trying to find a diplomatic word for careless, or criminally stupid or suicidal, and failing, ..... proud of their new-found ability to kill large areas of the strata creatures and render the shallows around these living coastlines safe for their expanding population.

            "But living in or under and perhaps controlling these strata creatures is yet another intelligent race whose land is quite literally in danger of dying all around them," Conway continued. "These people made the tool which came aboard Descartes, and judging by that gadget they are highly advanced indeed. But we still know nothing at all about them.

            "When it became clear that Surreshun's people were not the tool makers," Conway went on, "we asked ourselves where they would be most likely to be found, and the answer was in those areas where their living country was under attack. It was in this situation that I expected to find their medical people as well, and I did in fact find our transparent friend here. It saved my life, in its rather disconcerting fashion, and I'm convinced that it is the Drambon equivalent of a doctor. Unfortunately it does not seem to be able to communicate in any fashion that I can understand and, bearing in mind the fact that anyone can directly observe its innards without the necessity for X rays, there doesn't seem to be a localized gathering of nerve ganglia or indeed anything at all resembling a brain.

            "We badly need the help of its people," Conway added seriously, "which is the reason for bringing it here so that a specialist in e-t communications can succeed, perhaps, where the ship's contact experts and myself failed."

            He looked pointedly at O'Mara, who was looking thoughtfully at the leech-like Drambon. It, in turn, had put one of its eyes into a pseudopod and had extended it toward the ceiling so that it could look at the fragile, insect-like figure of the empath Prilicla. Prilicla had enough eyes to look everywhere at once.

            "Isn't it odd," said Colonel Skempton suddenly, "that one of your Drambons is heartless and the other appears to be brainless?"

            "Brainless doctors I am used to," said O'Mara dryly. "I communicate with them, on the whole successfully, every day. But this isn't your only problem?"

            Conway shook his head. "I've already said that we have to treat a small number of very large patients. Even with the assistance of all the Drambon medical people I would still need help in charting-and I do mean charting by photoreconnaissance-the extent of the trouble as accurately as possible and probing subsurface areas. X rays on this scale are impossible. A full-scale drilling operation to withdraw deep tissue samples would be of little use either, since the drill would be a short and impossibly fine needle. So we will need to investigate the diseased or damaged areas in person, using armored ground cars and, where possible, our hands and feet inside heavy-duty spacesuits. Entrance to the affected areas will be through natural body openings, and the exercise will go much faster if we have the help of people with medical training who do not need the protection of armored vehicles and suits. I'm thinking of species like the Chalders and Hudlars and Melfans who are armored already.

            "From Pathology," he went on, looking toward Thornnastor, "I would like suggestions for providing a cure by surgery rather than medication. Present indications are that the trouble will be largely the result of radiation poisoning, and while I realize that we can cure even advanced cases these days, the treatment may well be impossible to apply to patients this size, not to mention the fact that the regenerative medication required for only one of them could represent the total output of that drug from a dozen planets for many years. Hence the necessity for a surgical solution."

            Skempton cleared his throat and said, "I begin to see the scope of your problem, Doctor. My part will be in organizing transport and supplies for your medical people. I'd also suggest a full battalion of engineers to set up and maintain the special equipment...

            "To begin with," said Conway.

            "Naturally," said the Colonel a trifle coldly, "we shall continue to assist you in whatever-"

            "You misunderstood me, sir," said Conway. "I can't be sure just how much help we will need at the present time, but I had been thinking in terms of a full sector sub fleet armed with long-range lasers, surface penetrating torpedoes, tactical atomic weapons-clean, of course-and whatever other forms of frightfulness you can suggest that are both concentrated and capable of being directed accurately.

            "You see, Colonel," Conway concluded, "surgery on this scale will mean that the operation will be military rather than surgical." To O'Mara he added, "Those are a few of the reasons for my unscheduled return. The others are less urgent and..

            "Can damn well wait until this lot are sorted out," said O'Mara firmly.

            The meeting broke up shortly after that because neither Surreshun nor Conway could give any information on Drambo which was not already available in the Corps reports. O'Mara retreated into his inner office with the Drambon doctor, Thornnastor and Skempton returned to their quarters and Edwards, Mannon, Prilicla, and Conway, having first seen to the comfort of Surreshun in the AUGL tank, headed for the cafeteria reserved for warm-blooded oxygen breathers to refuel. The Hudlar and Melfan doctors went along to find out more about Drambo and to watch the others eat. As very recent additions to the hospital staff in the first flush of enthusiasm, they were spending every available minute observing and talking to e-ts.

            Conway knew the feeling. It was still very much with him, but nowadays he was practical enough to use as well as admire the enthusiasm of the new boys...

"The Chalders are tough and mobile enough to hold their own against the native predators," Conway said as they distributed themselves around a table designed for Tralthan FGLIs-the Earth-human DBDG tables were all taken, by Kelgians-and dialed their orders. "You Melfans are very fast movers on the sea bed and your legs, being mostly osseus material, are proof against the poisonous plants and spines growing on the ocean floor. Hudlars, however, while slow-moving do not have to worry about anything less than an armor-piercing shell hurting them and the water all over the planet is so thick with vegetable and animal life anxious to attach itself to any smooth surface that you could throw away your food spraying gear and live completely off the sea."

            "It sounds like heaven," said the Hudlar, its flat, translated tone making it impossible to tell whether or not it was being sarcastic. "But you will need large numbers of doctors in all three species-far too many to be supplied by the hospital even if everyone on the staff was allowed to volunteer.

            "We'll need hundreds of you," Conway replied, "and Drambo isn't heaven even for Hudlars. At the same time I thought there might be doctors-young, still restless, newly qualified people-anxious for e-t experience..

            "I'm not Prilicla," said Mannon, laughing, "but even I can sense that you are preaching to the converted. Do you like lukewarm steak, Conway?"

            For several minutes they concentrated on eating so that the gentle breeze produced by Prilicla's wings-it preferred to hover during meals, claiming that flying aided its digestion-would not ruin everything but the ice cream.

            "At the meeting," said Edwards suddenly, "you mentioned other, less urgent problems. I expect the recruiting of thick-skinned beasties like Garoth here was one of them. I'm afraid to ask about the others..

            Conway said, "We will need on-the-spot advice during this large-scale medical examination, which means doctors, nurses and medical technicians experienced in the processing and analysis of specimens covering the widest possible range of life-forms. I am going to have to talk Thornnastor into releasing some of his pathology staff..."

            Prilicla side-slipped suddenly and almost put one of its pencil-thin legs into Mannon's dessert. It was trembling slightly as it flew, a sure sign that someone at the table was radiating strong and complicated emotions.

            "I'm still not Prilicla," said Mannon, "but from the behavior of our empathic friend I would guess that you are seeking, and trying to justify, a much closer liaison with the pathology department and especially a pathologist called Murchison. Right, Doctor?"

            "My emotions are supposed to be privileged," said Conway.

            "I did not say a word," said Prilicla, who was still finding difficulty in maintaining a stable hover.

            Edwards said, "Who's Murchison?"

            "Oh, a female of the Earth-human DBDG classification," said Garoth through his translator. "A very efficient nurse with theater experience covering more than thirty different life-forms, who recently qualified as a pathologist senior grade. Personally I have found her pleasant and polite, so much so that I am able to ignore the, to me, physically repellent slabs of adipose overlaying much of her musculature."

            "And you're going to bring her to Drambo with you, Conway?" The Monitor Corps and its officers had very old-fashioned ideas about mixed crews, even on long survey missions.

            "Only," said Mannon gravely, "if he's given half a chance."

            "You should marry the girl, Conway."

            "He did."

            "This is a very strange establishment in some ways, Major," said Mannon, smiling, "full of odd and peculiar practices. Take sex, for instance. To a large number of the entities here it is either a continuing, involuntary process as public, and giving the about degree of stimulation, as breathing, or it is physiological earthquake which rocks them for perhaps three days in the year. People like these find it hard to understand the, to them, bewildering complications and ritualistic behavior connected with pairing off and mating in our species-although admittedly there are a few whose sex lives make ours look about as simple as crosspollination.

            "But the point I'm trying to make," Mannon went on, "is that the vast majority of our e-ts just do not understand why the female of our species should lose her identity, surrender that most precious of all possessions, her name. To many of them this smacks of slavery, or at least second-class citizenship, and to the others sheer stupidity. They don't see why an Earth-human female doctor, nurse or technician should change her identity and take the name belonging to another entity for purely emotional reasons and neither, if it comes to that, does the Records computer. So they retain their professional names, like actresses and similar professional females, and are very careful to use them at all times to avoid confusions of identity with e-ts who-"

            "He gets the point," said Conway dryly. "But sometime I'd like you to explain the difference between an amateur as opposed to a professional female."

            "They behave differently in private, of course," Mannon went on, ignoring him. "Some of them are sufficiently depraved to call each other by their first names.

            "We need a pathology team," said Conway, ignoring Mannon. "But even more we need local medical help. Surreshun's people, for physiological reasons, can give us only moral support, which means that everything depends on gaining the cooperation of our leech-like friends. This is where you come in, Prilicla. You were monitoring its emotional radiation during the meeting. Any ideas?"

            "I'm afraid not, friend Conway," said the empath. "During the whole of the meeting the Drambon doctor was conscious and aware, but it did not react to anything that was said or done or engage in any concentrated thinking. It emoted only feelings of well-being, repletion and self satisfaction."

            "It certainly did a good job on that Kelgian," said Edwards, "and to a leech the pint or so of blood it siphoned off..

            Prilicla waited politely for the interruption to cease, then went on, "There was a very brief heightening of interest detectable when members of the meeting first entered the room-the emotion was not one of curiosity, however, but more like the increase of awareness necessary for a cursory identification."

            "Was there any indication that the trip here had affected it?" asked Conway. "Impaired its physical or mental faculties, anything like that?"

            "It was thinking only contented thoughts," replied Prilicla, "so I would say not.~~

            They discussed the Drambon doctor until they were about to leave the dining hall, when Conway said, "O'Mara will be glad of your help, Prilicla, while he is putting our blood-sucking friend through his psychological hoops, so I would be grateful if you could monitor its emotional radiation while contact is being established. The Major may want to wait until communication is complete and a special translator pack has been programmed for the Drambon before contacting me. But I would like to have any useful information as you get it..."

            Three days later as he was about to board Descartes with Edwards and the first batch of recruits-a very carefully chosen few who would, he hoped, by their enthusiasm attract and instruct many more-the PA began quietly insisting that Doctor Conway contact Major O'Mara at once, its insistence reinforced by the repeated double chime which preceded most urgent signals. He waved the others ahead and went to the lock's communicator.

            "Glad I caught you," said the Chief Psychologist before Conway could do anything more than identify himself. "Listen, don't talk. Prilicla and I are getting nowhere with your Drambon medic. It emotes but we can't get it excited about anything so that we cannot even establish its likes and dislikes.

            "We know that it sees and feels," O'Mara went on, "but we aren't sure if it can hear or talk or, if it can, how it does these things. Prilicla thinks it may have a low form of empathy, but until we can put a few ripples into its even disposition there is no way of proving that. I am not admitting that I'm beaten, Conway, but you have handed us a problem which may have a very simple solution-"

            "Did you try it with the thought-controlled tool?"

            "That was the first, second and twenty-eighth thing we tried," said O'Mara sourly. "Prilicla detected a very slight heightening of interest consistent, it says, with the identification of a familiar object. But the Drambon made no attempt to control the gadget. I was saying that you handed us a problem. Maybe the simplest answer would be for you to hand us another just like it."

            The Chief Psychologist disliked having to give unnecessary explanations almost as much as people who were slow on the uptake, so Conway thought for a moment before saying, "So you would like me to bring back another Drambon medic so that you could observe and eavesdrop on their conversation when they meet, and reproduce the method on the translator . .

            "Yes, Doctor, and fast," said O'Mara, "before your Chief Psychologist needs a psychiatrist. Off."

            It was not possible for Conway to immediately seek out, kidnap or otherwise acquire another leech-like SRJH on his return to Drambo. He had a group of e-ts of widely varying dietary, gravity and atmosphere requirements to attend to and, while all three life-forms could exist without too much difficulty in the Drambon ocean, their quarters on Descartes had to have some of the comforts of home.

            They also had to be given some appreciation of the scope of the medical problem they were being asked to help solve, and this entailed many copter flights over the strata creatures. He showed them the great tracks of living "land" covered with the tiny, long-rooted plants which might or might not serve as the strata beasts' eyes-the leaves rolled back tightly to reveal their bright undersides when the helicopter's shadow passed over them, and opened out again a few seconds after it had passed. It was as if their shadow was a high-persistency yellow spot on a bright green radar screen. And he showed them the coastlines, which were much more dramatic.

            Here the sea predators, large and small, tore at each other and at the periphery of the great land beasts, stirring the thick, turgid ocean into yellow foam streaked and stained with red. It was in an area like this, where Conway had judged the strata beast's need for protection had been greatest, that he had found the leech-like SRJHs and where, as soon as he could possibly manage it, he must look for another.

            But this time he would have lots of willing and specialized help.

            Every day there was a message from O'Mara, different only in the mounting impatience evident between the lines. Prilicla and the Chief Psychologist were having no success with the Drambon doctor and had come to the conclusion that it used one of the exotic Visio tactile languages which were virtually impossible to reproduce without a detailed sight touch vocabulary.

The first expedition to the coast was in the nature of a rehearsal-at least, it started out that way. Camsaug and Surreshun took the lead, wobbling and wheeling along the uneven sea bed like a pair of great organic doughnuts. They were flanked by two crab-like Melfans who were easily capable of scuttling along twice as fast as the Drambons could roll, while a thirty-foot scaled and tentacled Chalder swam ponderously above them ready to discourage local predators with its teeth, claws and great bony club of a tail-although in Conway's opinion one look from any one of its four extensible eyes would be enough to discourage anything with the slightest will to live.

            Conway, Edwards, and Garoth traveled in one of the Corps's surface cruisers, a vehicle capable not only of moving over any conceivable topography but of going over, through or under the sea as well as being able to hover for a limited period in the air. They kept just far enough in the rear to keep everyone else in sight.

            They were headed toward a dead section of coast, a deep strip of the strata beast which Surreshun's people had killed to give themselves more protected rolling space. They had accomplished this by lobbing a series of very dirty atomic bombs ten miles inland and then waiting while the living coastline stopped killing and eating and drinking, and the coastline predators lost interest in the dead meat and left.

            Fallout did not concern the rollers because the prevailing wind blew inland. But Conway had deliberately selected a spot which was only a few miles from a stretch of coast which was still very much alive, so that with any luck their first examination might turn out to be something more than an autopsy.

            With the departure of the predators the sea's plant life had moved in. On Drambo the division between plant and animal life was rarely sharp and all animals were omnivorous. They had to travel along the coast for nearly a mile before finding a mouth that was not either closed too tightly or too badly overgrown to allow entry, but the time was not wasted because Camsaug and Surreshun were able to point out large numbers of dangerous plants that even the heavily armored e-ts should avoid whenever possible.

            The practice of extraterrestrial medicine was greatly simplified by the fact that the illnesses and infections of one species were not transmittable to another. But this did not mean that poisons or other toxic material secreted by e-t animals and plants could not kill, and on the Drambon sea bed the vegetation was particularly vicious. Several varieties were covered with poisoned spines and one acted as if it had delusions of being a vegetable octopus.

            The first usable mouth looked like an enormous cavern. When they followed the rollers inside the vehicle's spotlights showed pallid vegetation waving and wriggling slowly to the limit of vision. Surreshun and Camsaug were rolling out unsteady figure-eights on the densely overgrown floor and apologizing for the fact that they could not take the party any farther without risking being stopped.

            "We understand," said Conway, "and thank you."

            As they moved deeper into the enormous mouth the vegetation became sparse and more pallid, revealing large areas of the creature's tissue. It looked coarse and fibrous and much more like vegetable rather than animal material, even allowing for the fact that it had died several years earlier. The roof began suddenly to press down on them and the forward lights showed the first serious barrier, a tangle of long, tusk-like teeth so thick that they looked like the edge of a petrified forest.

            One of the Melfans was the first to report. It said, "I cannot be absolutely sure until Pathology checks my specimens, Doctor Conway, but the indications are that the creature's teeth are vegetable rather than animal osseous material. They grow thickly on both the upper and lower surfaces of the mouth and to the limit of our visibility. The roots grow transversely so that the teeth are free to bend forward and backward under steady pressure. In the normal position they are angled sharply toward the outer orifice and act as a killing barrier to large predators rather than as a means of grinding them into small pieces.

            "From the position and condition of several large cadavers in the area," the Melfan went on, "I would say that the creature's ingestion system is very simple. Sea water containing food animals of all sizes is drawn into a stomach or prestomach. Small animals slip through the teeth while large ones impale themselves, whereupon the inward current and the struggles of the animal concerned cause the teeth to bend inward and release it. I assume that the small animals are no problem but that the big ones could do serious damage to the stomach before the digestive system neutralizes them, so they have to be dead before they reach the stomach."

            Conway directed the spotlight toward the area containing the Melfan and saw it wave one of its mandibles. He said, "That sounds reasonable, Doctor. It wouldn't surprise me if the digestive processes are very slow indeed-in fact, I'm beginning to wonder if the creature is more vegetable than animal. An organism of normal flesh, blood, bone and muscle of this size would be too heavy to move at all. But it moves, and does everything else, very slowly. . ." He broke off and narrowed the beam for maximum penetration, then went on, "You had better get aboard so we can burn a way through those teeth."

            "No need, Doctor," said the Melfan. "The teeth have decayed and are quite soft and brittle. You can simply drive through them and we will follow."

            Edwards allowed the cruiser to sink to the floor, then moved it forward at a comfortable scuttling pace for Melfans. Hundreds of the long, discolored plant teeth snapped and toppled slowly through the cloudy water before they were suddenly in the clear.

            "If the teeth are a specialized form of plant life," said Conway thoughtfully, "they occupied a very sharply defined area, which suggests that someone is responsible for planting them."

            Grunting assent, Edwards checked to see that everyone had come through the tunnel they had just made, then he said, "The channel is widening and deepening again, and I can see another presumably specialized form of plant life. Big, isn't it? There's another. They're all over the place.

            "This is far enough," said Conway. "We don't want to lose sight of the way out.

            Edwards shook his head. "I can see openings on both sides just like this one. If the place is a stomach, and it looks big enough, there are several inlets."

            Angry suddenly, Conway said, "We know that there are hundreds of these mouths in this dead section alone and the number of stomachs is anybody's guess-great, flat, hollow caveins miles across if that radar isn't telling fluorescent lies. We aren't even nibbling at the problem!"

            Edwards made a sympathetic noise and pointed ahead. "They look like stalactites that have gone soft in the middle. I wouldn't mind taking a closer look."

            Even the Hudlar went out to have a closer look at the great, sharply curved pillars which supported the roof. Using their portable analyzers they were able to establish that the pillars were a part of the strata beast's musculature and not, as they had earlier thought, another form of plant life-although the surface of all the muscular supports in the area were covered with something resembling outsize seaweed. The blisters were nearly three feet across and looked about ready to burst. A Melfan taking a specimen of the underlying muscle accidentally touched one and it did burst, triggering off about twenty others in the vicinity. They released a thick, milky liquid which spread rapidly and dissolved in the surrounding water.

            The Melfan made untranslatable noises and scuttled backward.

            "What's wrong?" said Conway sharply. "Is it poisonous?"

            "No, Doctor. There is a strong acid content but it is not immediately harmful. If you were a water breather you would say that it stinks. But look at the effect on the muscle."

            The great pillar of muscle rooted firmly to both floor and roof was quivering, its sharp curve beginning to straighten out.

            "Yes," said Conway briskly, "this supports our theory about the creature's method of ingestion. But now I think we should return to Descartes-this area may not be as dead as we thought."

            Specialized teeth plants served as a filter and killing barrier to food drawn into the creature's stomach. Other symbiotic plants growing on the muscle pillars released a secretion which caused them to stiffen, expand the stomach, and draw in large quantities of food-bearing water. Presumably the secretion also served to dissolve the food, digest it for assimilation through the stomach wall or by other specialized plants- they had taken enough specimens for Thornnastor to be able to work out the digestive mechanism in detail. When the power of the digestive secretion had been diluted by the food entering the stomach their effect on the muscles diminished, allowing the pillars to partially collapse again and expel undigested material.

            Blisters were beginning to rupture off the other pillars now. By itself that did not mean that the beast was alive, only that a dead muscle could still respond to the proper stimulus. But the cavern roof was being pushed up and water was flowing in again.

            "I agree, Doctor," said Edwards, "let's get out of here. But could we leave by a different mouth-we might learn something from a stretch of new scenery.

            "Yes," said Conway, with the uncomfortable feeling that he should have said no. If dead muscles could twitch, what other forms of involuntary activity were possible to the gigantic carcass? He added, "You drive, but keep the cargo hatch and personnel lock open-I'll stay outside with the e-ts .

            A few minutes later Conway was hanging onto a handy projection as the vehicle followed the e-ts into a different mouth opening. He hoped it was a mouth and not a connection with something deeper inside the beast, because Edwards reported that it was curving toward a live area of coast. But before the lowering temperature of his feet could affect his speech centers enough for him to order them back the way they had come, there was an interruption.

            "Major Edwards, stop the cruiser, please," said one of the Melfans. "Doctor Conway, down here. I think I have found a dead.. . colleague."

            It was a Drambon SRJH, no longer transparent but milky and shriveled with a long, incised wound traversing its body, drifting and bumping along the floor.

            "Thornnastor will be pleased with you, friend," said Conway enthusiastically. "And so will O'Mara and Prilicla. Let's get it aboard with the other specimens. Oh, I'm not a water breather, but..

            "It doesn't," the Melfan replied to the unspoken question. "I'd say that it was too recently dead to be offensive.~~

            The Chalder came sweeping back, its tentacles gripped the dead SRJH and transferred it to the refrigerated specimen compartment, then it returned to its position. A few seconds later one flat, toneless, translated word rasped in their receivers.

            "Company. ~

            Edwards directed all his lights ahead to show a fighting, squirming menagerie practically filling the throat ahead. Conway identified two kinds of large sea predators who had obviously been able to batter a way through the brittle teeth, several smaller ones, about ten SRJHs and a few large-headed, tentacled fish that he had never seen before. It was impossible to tell at first which were fighting which or even if it mattered to the beings concerned.

            Edwards dropped the vehicle to the floor. "Back inside! Quickly!"

            Half-running, half-swimming toward the vehicle, Conway envied the underwater mobility of the Melfans so' much that it hurt. He overtook the Hudlar who had the jaws of a big predator locked on its carapace. Just above him one of the new life-forms had an SRJH wrapped around it, the Drambon doctor already turning red as it treated its patient in the only way it knew how. There was a deep, reverberating clang as another predator charged the cruiser, smashing two of their four lights.

            "Into the cargo hold!" Edwards shouted hoarsely. "We've no time to fiddle about with personnel locks!"

            "Get off me, you fool," said the Hudlar with the predator on its back. "I'm inedible."

            "Conway, behind you!"

            Two big predators were coming at him along the bottom while the Chalder was shooting in from the flank. Suddenly there was a Drambon doctor undulating rapidly between the leading predator and Conway. It barely touched the beast but the predator went into a muscular spasm so violent that parts of its skeleton popped white through the skin.

            So you can kill as well as cure, thought Conway gratefully as he tried to avoid the second predator. The Chalder arrived then and with a swipe of its armored tail cleared the Hudlar's back while simultaneously its enormous maw opened and crashed shut on the second predator's neck.

            "Thank you, Doctor," said Conway. "Your amputation technique is crude but effective."

            "All too often," replied the Chalder, "we must sacrifice neatness for speed..."

            "Stop chattering and get in!" yelled Edwards.

            "Wait! We need another local medic for O'Mara," began Conway, gripping the edge of the hatch. There was a Drambon doctor drifting a few yards away, bright red and obliviously wrapped around its patient. Conway pointed and to the Chalder said, "Nudge it inside, Doctor. But be gentle, it can kill, too."

            When the hatch clanged shut a few minutes later the cargo hold contained two Melfans, a Hudlar, the Chalder, the Drambon SRJH with its patient and Conway. It was pitch dark. The vehicle shuddered every few seconds as predators crashed against its hull, and conditions were so cramped that if the Chalder moved at all everyone but the armor-plated Hudlar would have been mashed flat. Several years seemed to go past before Edward's voice sounded in Conway's helmet.

            "We're leaking in a couple of places, Doctor-but not badly and it shouldn't worry water breathers in any case. The automatic cameras have some good stuff on internal life-forms being helped by local medics. O'Mara will be very pleased. Oh, I can see teeth ahead. We'll soon be out of this

            Conway was to remember that conversation several weeks later at the hospital when the living and dead specimens and film had been examined, dissected, and viewed so often that the leech-like Drambons undulated through his every dream.

            O'Mara was not pleased. He was, in fact, extremely displeased-with himself, which made things much worse for the people around him.

            "We have examined the Drambon medics singly and together, friend Conway," said Prilicla in a vain attempt to render the emotional atmosphere in the room a little more pleasant. "There is no evidence that they communicate verbally, visually, tactually, telepathically, by smell or any other system known to us. The quality of their emotional radiation leads me to suspect that they do not communicate at all in the accepted sense. They are simply aware of other beings and objects around them and, by using their eyes and a mechanism similar to the empathic faculty which my race possesses, are able to identify friend and foe-they attacked the Drambon predators without hesitation, remember, but ignored the much more visually frightening Chalder doctor who was feeling friendship for them.

            "So far as we have been able to discover," Prilicla went on, "its emphatic faculty is highly developed and not allied to intelligence. The same applies to the second Drambon native you brought back, except that it is .

            "Much smarter," O'Mara finished sourly. "Almost as smart as a badly retarded dog. I don't mind admitting that for a while I thought our failure to communicate may have been due to a lack of professional competence in myself. But now it is clear that you were simply wasting our time giving sophisticated tests to Drambon animals."

            "But that SRJH saved me."

            "A very highly specialized but nonintelligent animal," said O'Mara firmly. "It protects and heals friends and kills enemies, but it does not think about it. As for the new specimen you brought in, when we exposed it to the thought-controlled tool it emoted awareness and caution-a feeling similar to our emotional radiation if we were standing close to a bare power line-but according to Prilicla it did not think at or even about the gadget.

            "So I'm sorry, Conway," he ended, "we are still looking for the species responsible for making those tools, and for intelligent local medical assistance with your own problem."

            Conway was silent for a long time, staring at the two SRJHs on O'Mara's floor. It seemed all wrong that a creature responsible for saving his life should have done so without thought or feeling. The SRJH was simply a specialist like the other specialized animals and plants inhabiting the interior of the great strata beasts, doing the work it had evolved to do. Chemical reactions were so slow inside the strata creatures-the material was too diluted for them to be otherwise since its blood might be little more than slightly impure water-that specialized plant and animal symbiotes could produce the secretions necessary for muscle activity, endocrine balance, supplying nourishment to and removing waste material from large areas of tissue. Other specialized symbiotes handled the respiration cycle and gave vision of a kind on the surface.

            "Friend Conway has an idea," said Prilicla.

            "Yes," said Conway, "but I would like to check it by getting the dead SRJH up here. Thornnastor hasn't done anything drastic to it yet, and if something should happen to it we can easily get another. I would like to face the two living SRJHs with a dead colleague.

            "Prilicla says that they do not emote strongly about anything," Conway added. "They reproduce by fission so there can be no sexual feeling between them. But the sight of one of their own dead should cause some kind of reaction."

            O'Mara stared hard at Conway as he said, "I can tell by the way Prilicla is trembling and by the smug look on your face that you think you have the answer. But what is likely to happen? Are these two going to heal and resuscitate it? Oh, never mind, I'll wait and let you have your moment of medical drama. .

            When the dead SRJH arrived Conway quickly slid it from the litter onto the office floor and waved O'Mara and Prilicla back. The two living SRJHs were already moving purposefully toward the cadaver. They touched it, flowed around and over it and for about ten minutes were very busy. When they had finished there was nothing left.

            "No detectable change in emotional radiation, no evidence of grief," said Prilicla. It was trembling but its own feelings of surprise were probably responsible for that.

            "You don't look surprised, Conway," said O'Mara accusingly.

            Conway grinned and said, "No, sir. I'm still disappointed at not making contact with a Drambon doctor, but these beasties are a very good second best. They kill the strata beast's enemies, heal and protect its friends and tidy up the debris. Doesn't that suggest something to you? They aren't doctors, of course, just glorified leucocytes. But there must be millions of them, and they're all on our side. .

            "Glad you're satisfied, Doctor," said the Chief Psychologist, looking pointedly at his watch.

            "But I'm not satisfied," said Conway. "I still need a senior pathologist trained in and with the ability to use the hospital's facilities-one particular pathologist. I need to maintain a close liaison with-"

            "The closest possible liaison," said O'Mara, grinning suddenly. "I quite understand, Doctor, and I shall urge it with Thornnastor just as soon as you've closed the door...

MAJOR OPERATION

On the whole weird and wonderful planet there were only thirty-seven patients requiring treatment, and they varied widely both in size and in their degree of physical distress. Naturally it was the patient who was in the greatest distress who was being treated first, even though it was also the largest-so large that at their scout ship's sub orbital velocity of six thousand plus miles per hour it took just over nine minutes to travel from one side of the patient to the other.

            "It's a large problem," said Conway seriously, "and even altitude doesn't make it look smaller. Neither does the shortage of skilled help."

            Pathologist Murchison, who was sharing the tiny observation blister with him, sounded cool and a little on the defensive as she replied, "I have been studying all the Drambon material long before and since my arrival two months ago, but I agree that seeing it like this for the first time really does bring the problem home to one. As for the shortage of help, you must realize, Doctor, that you can't strip the hospital of its staff and facilities for just one patient even if it is the size of a subcontinent- there are thousands of smaller and more easily curable patients with equal demands on us.

            "And if you are still suggesting that I, personally, took my time in getting here," she ended hotly, "I came just as soon as my chief decided that you really did need me, as a pathologist."

            "I've been telling Thornnastor for six months that I needed a top pathologist here," said Conway gently. Murchison looked beautiful when she was angry, but even better when she was not. "I thought everybody in the hospital knew why I wanted you, which is one reason why we are sharing this cramped observation blister, looking at a view we have both seen many times on tape and arguing when we could be enjoying some unprofessional behavior-"

            "Pilot here," said a tinny voice in the blister's 'speaker. "We are losing height and circling back now and will land about five miles east of the terminator. The reaction of the eye plants to sunrise is worth seeing."

            "Thank you," said Conway. To Murchison he added, "I had not planned on looking out the window."

            "I had," she said, punching him with one softly clenched fist on the jaw. "You I can see anytime."

            She pointed suddenly and said, "Someone is drawing yellow triangles on your patient."

            Conway laughed. "I forgot, you haven't been involved with our communications problems so far. Most of the surface vegetation is light sensitive and, some of us thought, might act as the creature's eyes. We produce geometrical and other figures by directing a narrow, intense beam of light from orbit into a dark or twilight area and moving it about quickly. The effect is something like that of drawing with a high persistency spot on a vision screen. So far, there has been no detectable reaction.

            "Probably," he went on, "the creature can't react even if it wanted to, because eyes are sensory receptors and not transmitters. After all, we can't send messages with our eyes.

            "Speak for yourself," she said.

            "Seriously," Conway said, "I'm beginning to wonder if the strata creature itself is highly intelligent...

            They landed shortly afterward and stepped carefully onto the springy ground, crushing several of the vegetable eyes with every few yards of progress. The fact that the patient had countless millions of other eyes did not make them feel any better about the damage inflicted by their feet.

            When they were about fifty yards from the ship, she said suddenly, "If these plants are eyes-and it is a natural assumption, since they are sensitive to light-why should it have so many in an area where danger threatens so seldom? Peripheral vision to coordinate the activity of its feeding mouths would be much more useful."

            Conway nodded. They knelt carefully among the plants, their long shadows filled with the yellow of tightly closed leaves. He indicated their tracks from the entry lock of the ship, which were also bright yellow, and moved his arms about so as to partly obscure some of the plants from the light. Leaves partially in shade or suffering even minor damage reacted exactly as those completely cut off from the light. They rolled up tight to display their yellow undersides.

            "The roots are thin and go on forever," he said, excavating gently with his fingers to show a whitish root which narrowed to the diameter of thin string before disappearing from sight. "Even with mining equipment or during exploratories with diggers we haven't been able to find the other end of one. Have you learned anything new from the internals?"

            He covered the exposed root with soil, but kept the palms of both hands pressed lightly against the ground.

            Watching him, she said, "Not very much. Light and darkness, as well as causing the leaves to open out or roll up tight, causes electrochemical changes in the sap, which is so heavily loaded with mineral salts that it makes a very good conductor. Electrical pulses produced by these changes could travel very quickly from the plant to the other end of the root. Er, what are you doing, dear, taking its pulse?"

            Conway shook his head without speaking, and she went on. "The eye plants are evenly distributed over the patient's top surface, including those areas containing dense growths of the air-renewal and waste-elimination types, so that a shadow or light stimulus received anywhere on its surface is transmitted quickly-almost instantaneously, in fact-to the central nervous system via this mineral-rich sap. But the thing which bothers me is what possible reason could the creature have for evolving an eyeball several hundred miles across?"

            "Close your eyes," said Conway, smiling. "I'm going to touch you. As accurately as you can, try to tell me where."

            "You've been too long in the company of men and e-ts, Doctor," she began, then broke off, looking thoughtful.

            Conway began by touching her lightly on the face, then he rested three fingers on top of her shoulder and went on from there.

            "Left cheek about an inch from the left side of my mouth," she said. "Now you've rested your hand on my shoulder. You seem to be rubbing an X onto my left bicep. Now you have a thumb and two, maybe three, fingers at the back of my neck just on the hairline... Are you enjoying this? I am."

            Conway laughed. "I might if it wasn't for the thought of Lieutenant Harrison watching us and steaming up the pilot's canopy with his hot little breath. But seriously, you see what I'm getting at, that the eye plants have nothing to do with the creature's vision but are analogous to pressure- , pain- or temperature-sensitive nerve endings?"

            She opened her eyes and nodded. "It's a good theory, but you don't look happy about it."

            "I'm not," said Conway sourly, "and I'd like you to shoot as many holes in it as possible. You see, the complete success of this operation depends on us being able to communicate with the beings who produced the thought-controlled tools. Up until now I had assumed that these beings would be comparable in size to ourselves even if their physiological classification would be completely alien, and that they would possess the usual sensory equipment of sight, hearing, taste, touch and be capable of being reached through any or all of these channels. But now the evidence is piling up in favor of a single intelligent life-form, the strata creature itself, which is naturally deaf, dumb and blind so far as we can see. The problem of communicating even the simplest concepts to it is-"

            He broke off, all his attention concentrated on the palm of one hand which was still pressed against the ground, then said urgently, "Run for the ship."

            They were much less careful about stepping on plants on the way back, and as the hatch slammed shut behind them Harrison's voice rattled at them from the lock communicator.

            "Are we expecting company?"

            "Yes, but not for a few minutes," said Conway breathlessly. "How much time do you need to get away, and can we observe the tools' arrival through something bigger than this airlock port?"

            "For an emergency liftoff, two minutes," said the pilot, "and if you come up to Control you can use the scanners, which check for external damage.

            "But what were you doing, Doctor?" Harrison resumed as they entered his control position. "I mean, in my experience the front of the bicep is not considered to be a zone of erotic stimulation."

            When Conway did not answer he looked appealingly at Murchison.

            "He was conducting an experiment," she said quietly, "designed to prove that I cannot see with the nerve endings of my upper arm. When we were interrupted he was proving that I did not have eyes in the back of my neck, either."

            "Ask a silly question. . ." began Harrison.

            "Here they come," said Conway.

            They were three semicircular disks of metal which seemed to flicker into and out of existence on the area of ground covered by the long morning shadow of the scout ship. Harrison stepped up the magnification of his scanners, which showed that the objects did not so much appear and disappear as shrink rhythmically into tiny metal blobs a few inches across, then expand again into flat, circular blades which knifed through the surface. There they lay flat for a few seconds among the shadowed eye plants, then suddenly the discs became shallow inverted bowls. The change was so abrupt that they bounced several yards into the air to land about twenty feet away. The process was repeated every few seconds, with one disc bouncing rapidly toward the distant tip of their shadow, the second zig-zagging to chart its width and the third heading directly for the ship.

            "I've never seen them act like that before," said the lieutenant.

            "We've made a long, thin itch," said Conway, "and they've come to scratch it. Can we stay put for a few minutes?"

            Harrison nodded, but said, "Just remember that we'll still be staying put for two minutes after you change your mind."

            The third disk was still coming at them in five-yard leaps along the center of their shadow. He had never before seen them display such mobility and coordination, even though he knew that they were capable of taking any shape their operators' thought at them, and that the complexity of the shape and the speed of the change were controlled solely by the speed and clarity of thought of the user's mind.

            "Lieutenant Harrison has a point, Doctor," said Murchison suddenly. "The early reports say that the tools were used to undercut grounded ships so that they would fall inside the strata creature, presumably for closer examination at its leisure. On those occasions they tried to undercut the object's shadow, using the shaded eye plants as a guide to size and position. But now, to use your own analogy, they seem to have learned how to tell the itch from the object causing it."

            A loud clang reverberated along the hull, signaling the arrival of the first tool. Immediately the other two turned and headed after the first, and one after the other they bounced high into the air, higher even than the control position, to arch over and crash against the hull. The damage scanners showed them strike, cling for a few seconds while they spread over hull projections like thin, metallic pancakes, then fall away. An instant later they were clanging and clinging against a different section of hull. But a few seconds later they stopped clinging because, just before making contact, they grew needle points which scored bright, deep scratches in the plating.

            "They must be blind," said Conway excitedly. "The tools must be an extension of the creature's sense of touch, used to augment the information supplied by the plants. They are feeling us for size and shape and consistency."

            "Before they discover that we have a soft center," said Harrison firmly, "I suggest that we make a tactical withdrawal, or even get the hell out.

            Conway nodded. While Harrison played silent tunes on his control panels he explained that the tools were controllable by human minds up to a distance of about twenty feet and that beyond this distance the tool users had control. He told her to think blunt shapes at them as soon as they came into range, any shape so long as it did not have points or cutting edges .

            "No, wait," he said as a better idea struck him. "Think wide and flat at them, with an aerofoil section and some kind of vertical projection for stabilization and guidance. Hold the shape while it is falling and glide it as far away from the ship as possible. With luck it will need three or four jumps to get back."

            Their first attempt was not a success, although the shape which finally stuck the ship was too blunt and convoluted to do serious damage. But they concentrated hard on the next one, holding it to a triangle shape only a fraction of an inch thick and with a wide central fin. Murchison held the overall shape while Conway thought-warped the trailing edges and stabilizer so that it performed a balanced vertical bank just outside the direct-vision panel and headed away from the ship in a long, flat glide.

            The glide continued long after it passed beyond their range of influence, banking and wobbling a little, then cutting a short swathe through the eye plants before touching down.

            "Doctor, I could kiss you. . ." she began.

            "I know you like playing with girls and model airplanes, Doctor," Harrison broke in dryly, "but we lift in twenty seconds. Straps."

            "It held that shape right to the end," Conway said, beginning to worry for some reason. "Could it have been learning from us, experimenting perhaps?"

            He stopped. The tool melted, flowed into the inverted bowl shape and bounced high into the air. As it began to fall back it changed into glider configuration, picking up speed as it fell, then leveled out a few feet above the surface and came sweeping toward them. The leading edges of its wings were like razors. Its two companions were also aloft in glider form, slicing the air toward them from the other side of the ship.

"Straps."

            They hit their acceleration couches just as the three fast-gliding tools struck the hull, by accident or design, cutting off two of the external vision pickups. The one which was still operating showed a three-foot gash torn in the thin plating with a glider embedded in the tear, changing shape, stretching and widening it. Probably it was a good thing that they could not see what the other two were doing.

            Through the gash in the plating Conway could see brightly colored plumbing and cable runs which were also being pushed apart by the tool. Then that screen went dead as well just as takeoff boost rammed him deep into the couch.

            "Doctor, check the stern for stowaways," said Harrison harshly as the initial acceleration began to taper off. "If you find any, think safe shapes at them-something which won't scramble anymore of my wiring. Quickly."

            Conway had not realized the full extent of the damage, only that there were more red lights than usual winking from the control board. The pilot's fingers were moving over his panels with such an intensity of gentleness that the harshness in his voice made it sound as if it was coming from a completely different person.

            "The aft pickup," said Conway reassuringly, "shows all three tools gliding in pursuit of our shadow.

            For a time there was silence broken only by the tuneless whistling of air through torn plating and unretracted scanner supports. The surface wobbled past below them and the ship's motion made Conway feel that it was at sea rather than in the air. Their problem was to maintain height at a very low flying speed, because to increase speed would cause damaged sections of the hull to peel off or heat up due to atmospheric friction, or increase the drag to such an extent that the ship would not fly at all. For a vessel which was classed as a supersonic glider for operations in atmosphere their present low speed was ridiculous. Harrison must be holding onto the sky with his fingernails.

            Conway tried hard to forget the lieutenant's problems by worrying aloud about his own.

            "I think this proves conclusively that the strata creatures are our intelligent tool users," he said. "The high degree of mobility and adaptability shown by the tools makes that very plain. They must be controlled by a diffuse and not very strong field of mental radiation conducted and transmitted by root networks and extending only a short distance above the surface. It is so weak that an average Earth-human or e-t mind can take local control.

            "If the tool users were beings of comparable size and mental ability to ourselves," he went on, trying not to look at the landscape lurching past below them, "they would have to travel under and through the surface material as quickly as the tools were flying over it if they were to maintain control. To burrow at that speed would require them being encased in a self-propelled armor-piercing shell. But this does not explain why they have ignored our attempts at making wide-range contact through remote-control devices, other than by reducing the communication modules to their component pieces..

            "If the range of mental influence pervades its whole body," Murchison broke in, "would that mean that the creature's brain is also diffuse? Or, if it does have a localized brain, where is it?"

            "I favor the idea of a centralized nervous system," Conway replied, in a safe and naturally well-protected area-probably close to the creature's underside where there is a plentiful supply of minerals and possibly in a natural hollow in the subsurface rock. Eye plant and similar types of internal root networks which you've analyzed tend to become more complex and extensive the closer we go to the subsurface, which could mean that the pressure-sensitive network there is augmented by the electro vegetable system which causes muscular movement as well as the other types whose function and purpose are still unknown to us. Admittedly the nervous system is largely vegetable, but the mineral content of the root systems means that electrochemical reactions generated at any nerve ending will transmit impulses to the brain very quickly, so there is probably only one brain and it could be situated anywhere."

            She shook her head. "In a being the size of a subcontinent, with no detectable skeleton or osseous structure to form a protective casing and whose body, relative to its area, resembles a thin carpet, I think more than one would be needed-one central brain, anyway, plus a number of neural substations. But the thing which really worries me is what do we do if the brain happens to be in or dangerously close to the operative field."

            "One thing we can't do," Conway replied grimly, "is delay the op. Your reports make that very clear."

            She had not been wasting time since coming to Drambo and, as a result of her analysis of thousands of specimens taken by test bores, diggers and exploring medics from all areas and levels of its far-flung body, she was able to give an accurate if not completely detailed picture of the creature's current physiological state.

            They already knew that the metabolism of the strata creature was extremely slow and that its muscular reactions were closer to those of a vegetable than an animal. Voluntary and involuntary muscles controlling mobility, ingestion and digestion, circulation of its working fluid and the breaking down of waste products were all governed or initiated by the secretions of the specialized plants. But it was the plants comprising the patient's nervous system with their extensive root networks which had suffered worst in the roller fallout, because they had allowed the surface radioactivity to penetrate deep inside the strata creature. This had killed many plant species and had also caused the deaths of thousands of internal animal organisms whose purpose it was to control the growth of various forms of specialized vegetation.

            There were two distinct types of internal organisms and they took their jobs very seriously. The large-headed farmer fish were responsible for cultivating and protecting benign growth and destroying all others- for such a large creature, the patient's metabolic balance was remarkably delicate. The second type, which were the being's equivalent of leucocytes, assisted the farmer fish in plant control and directly if one of the fish became injured or unwell. They were also cursed with the tidy habit of eating or otherwise absorbing dead members of their own or the fish species, so that a very small quantity of radioactive material introduced by the roots of surface plants could be responsible for killing a very large number of leucocytes, one after another.

            And so the dead areas which had spread far beyond the regions directly affected by roller fallout were caused by the uncontrolled proliferation of malignant plant life. The process, like decomposition, was irreversible. The urgent surgical removal of the affected areas was the only solution.

            But the report had been encouraging in some respects. Minor surgery had already been performed in a number of areas to check on the probable ecological effects of large masses of decomposing animo vegetable material on the sea or adjacent living strata creature, and to devise methods of radioactive decontamination on a large scale. It had been found that the patient would heal, but slowly; that if the incision was widened to a trench one hundred feet across, then the uncontrolled growth in the excised section would not spread to infect the living area, although regular patrols of the incision to make absolutely sure of this were recommended. The decomposition problem was no problem at all-the explosive growth rate continued until the plant life concerned used up the available material and died. On land the residue would subside into a very rich loam and make an ideal site for a self-supporting base if medical observers were needed in the years to come. In the case of material sliding off shelving coastlines into the sea, it simply broke up and drifted to the seabed to form an edible carpet for the rollers.

            Certain areas could not be treated surgically, of course, for the same reason that Shylock had to forego his pound of flesh. These were relatively small trouble spots far inland, whose condition was analogous to a severe skin cancer, but limited surgery and incredibly massive doses of medication were beginning to show results.

            "But I still don't understand its hostility toward us," Murchison said nervously as the ship went into a three-dimensional skid and lost a lot of height. "After all, it can't possibly know enough about us to hate us like that."

            The ship was passing over a dead area where the eye plants were discolored and lifeless and did not react to their shadow. Conway wondered if the vast creature could feel pain or if there was simply a loss of sensation when parts of it died. In every other life-form he had ever encountered, and he had met some really weird ones at Sector General, survival was pleasure and death brought pain-that was how evolution kept a race from just lying down and dying when the going got tough. So the strata creature almost certainly had felt pain, intense pain over hundreds of square miles, when the rollers had detonated their nuclear weapons. It had felt more than enough pain to drive it mad with hatred.

            Conway cringed inwardly at the thought of such vast and unimaginable pain. Several things were becoming very clear to him.

            "You're right," he said. "They don't know anything at all about us, but they hate our shadows. This one in particular hates them because the aircraft carrying the sea-rollers' atomic bombs produced a shadow not unlike ours just before large tracts of the patient's body were fried and irradiated."

            "We land in four minutes," said Harrison suddenly. "On the coast, I'm afraid, because this bucket has too many holes in it to float. Descartes has us in sight and will send a copter.

            The pilot's face made Conway fight the urge to laugh. It looked like that of a half made-up clown. Furious concentration had drawn Harrison's brows into a ridiculous scowl while his lower lip, which he had been chewing steadily since takeoff, was a wide, blood-red bow of good humor.

            Conway said, "The tools can't operate in this area and, except for a little background radiation caused by fallout, there is no danger. You can land safely."

            "Your trust in my professional ability," said the pilot, "is touching." From their condition of unlevel flight they curved into a barely controlled, tail-first dive. The surface crept, then rushed up at them. Harrison checked the rush with full emergency thrust. There were metallic tearing noises and the rest of the lights on his board turned red.

            "Harrison, pieces of you are dropping off.. ." began Descartes' radioman, then they touched down.

            For days afterward the observers argued about it, trying to decide whether it had been a landing or a crash. The shock-absorber legs buckled, the stern section took some more of the shock as it tried to telescope amidships and the acceleration couches took the rest-even when the ship toppled, crashed onto its side and a broad, flickering wedge of daylight appeared in the plating a few feet away. The rescue copter was almost on top of them.

            "Everybody out," said Harrison. "The pile shielding has been damaged."

            Looking at the dead and discolored surface around them, Conway thought again of his patient. Angrily, he said, "A little more radiation hereabout won't make much difference."

            "To your patient, no," said the lieutenant urgently. "But perhaps selfishly I was thinking of my future offspring. After you."

            During the short trip to the mother ship Conway stared silently out of the port beside him and tried hard not to feel frightened and inadequate. His fear was due to reaction after what could easily have been a fatal crash plus the thought of an even more dangerous trip he would have to make in a few days' time, and any doctor with a patient who stretched beyond the limits of visibility in all directions could not help feeling small. He was a single microbe trying to cure the body containing it, and suddenly he longed for the normal doctor-patient relationships of his hospital-even though very few of his patients or colleagues could be considered normal.

            He wondered if it might not be better to have sent a general to medical school than to give a doctor control of a whole sector sub fleet.

            Only six of the Monitor Corps heavies were grounded on Drambo, their landing legs planted firmly in the shallows a few miles off one of the dead sections of coastline. The others filled the morning and evening sky like regimented stars. His medical teams were grouped in and around the grounded ships, which rose out of the thick, soupy sea like gray beehives. The Earth-humans like himself lived on board while the e-ts, none of whom breathed air, were quite happy roughing it on the sea bed.

            He had called what he hoped would be the final pre-op meeting in the cargo hold of Descartes, which was filled with Drambon sea water whose content of animal and plant, life had been filtered out so that the beam of the projector would have a sporting chance of fighting its way to the screen attached to the forward bulkheads.

            Protocol demanded that the Drambons present opened the proceedings. Watching their spokesman, Surreshun, rolling like a great flaccid doughnut around the clear space in the center of the deck, Conway wondered once again how such a ridiculously vulnerable species had been able to survive and evolve a highly complex, technology-based culture- though it was just possible that an intelligent dinosaur would have had similar thoughts about early man.

            Surreshun was followed by Garoth, the Hudlar Senior Physician who was in charge of the patient's medical treatment. Garoth's chief concern was with the devising and implementation of artificial feeding in areas where incisions would cut the throat tunnels between the coastal mouths and the inland prestomachs. Again unlike Surreshun, it did not say very much but let the projector do all the talking.

            The big screen was filled by a picture of an auxiliary mouth shaft situated about two miles inland of the planned incision line. Every few minutes a copter or small supply ship grounded beside the shaft discharged its load of freshly dead animal life from the coastal shallows and departed while corpsmen with loaders and earth-moving machinery pushed the food over the lip. Possibly the amount and quality of the food was less than that which was drawn in naturally, but when the throat was sealed during the major operation this would be the only way that large areas of the patient could be supplied with food.

            Aseptic procedures were impossible in an operation on this scale so that pumping equipment drawing sea water from the coast was drawn through large-diameter plastic piping. It poured in a steady stream- except when tools cut the pipeline-into the food shaft, supplying the strata creature with needed working fluid and at the same time wetting the walls so that leucocytes could be slipped down from time to time to combat the effects of any dangerous plant life which might have been introduced during feeding.

            They were seeing a drill, of course, performed at one of the feeding installations a few days earlier, but there were more than fifty auxiliary mouths in a similar state of readiness strung out along the proposed incision line.

            Suddenly there was a silvery blur of motion on the ground beside the pump housing and a corpsman hopped a few yards on one foot before falling to the ground. His boot with his other foot still in it lay on its side where he had been standing and the tool, no longer silvery, was already cutting its way beneath the blood-splashed surface.

            "Tool attacks are increasing in frequency and strength," said Garoth in Translated. "They are also displaying considerable initiative. Your idea of clearing an area around the feeding installations of all eye plants so that the tools would have to operate blind, and would have to bounce around feeling for targets, worked only for a short time, Doctor. They devised a new trick, that of sliding along a few inches below the surface, blind, of course, then suddenly extruding a point or a cutting blade and stabbing or swinging with it before retreating under the surface again. If we can't see them, mental control is impossible, and guarding every working corpsman with another carrying a metal detector has not worked very well so far-it has simply given the tool a better chance of hitting someone.

            "And just recently," Garoth concluded, "there are indications of the tools linking up into five- , six- and in one case ten-unit combinations. The corpsman who reported this died a few seconds later before he was able to finish his report. The condition of his vehicle later supports this theory, however."

            Conway nodded grimly and said, "Thank you, Doctor. But now I'm afraid that you'll have to withstand air attacks as well. On the way here we taught the patient how gliders work, and it learned fast.. ." He went onto describe the incident, adding the latest pathological findings and their deductions and theories on the nature of their patient. As a result the meeting quickly became a debate and was degenerating into a bitter argument before he had to pull rank and get his human and e-t doctors back to a state of clinical detachment.

            The heads of the Melfan and Chalder teams made their report practically as a duet. Like Garoth they had both been concerned with the no surgical aspects of the patient's treatment. To a hypothetical observer ignorant of the true scope of their problem this medical treatment could have been mistaken for a very widespread mining operation, agriculture on an even larger scale and mass kidnapping. Both were strongly convinced, and Conway agreed with them, that the wrong way to treat a skin cancer was by amputation of the affected limb.

            The amounts of radioactive material deposited by fallout in the central areas were relatively small, and their effects spread fairly slowly into the depths of the patient's body. But even this condition would be ultimately fatal if something was not done to check it. And, since the areas affected by light fallout were too numerous and occurred in too many inoperable locations, they had skinned off the poisoned surface with earth-moving machinery and pushed it into heaps for later decontamination. The remainder of the treatment involved helping the patient to help itself.

            A picture appeared suddenly on the screen of a section of subsurface tunnel under one of the areas affected by fallout. There were dozens of life-forms in the tunnel, most of them farmer fish with stubby arms sprouting from the base of their enlarged heads while the others drifted or undulated toward the observer's position like great, transparent slugs.

            For a living section of the strata creature it looked none too healthy. The farmer fish, whose function was the cultivation and control of internal plant life, moved slowly, bumping into each other and the leucocytes which, normally transparent, were displaying the milky coloration which occurred shortly before death. The radiation sensor readings left no doubt as to what they were dying from.

            "These specimens were rescued shortly afterward," said the Chalder, "and transferred to sick bays in the larger ships and to Sector General. Both fish and leeches respond to the same decontamination and regeneration treatments given to our own people who have been exposed to a radiation overdose. They were then returned to carry on their good work."

            "That being," the Melfan joined in, "absorbing the radiation from the nearest poisoned plant or fish and getting themselves sick again."

            O'Mara had accused Conway of treating Sector General like some kind of e-t sausage machine, although the hospital was curing everything Drambon that they possibly could, and the Monitor Corps medics had merely looked long-suffering when they weren't looking extremely busy.

            By themselves neither the hospital nor treatment facilities on the capital ships were enough to swing the balance. To really allow the patient to fight these local infections required massive transfusions of the leucocyte life-form from other, and healthier, strata creatures.

            When he had first suggested the transfusion idea Conway had been worried in case the patient would reject what were, in effect, another creature's antibodies. But this had not happened, and the only problems encountered were those of transportation and supply as the first single, carefully selected kidnappings became continual wholesale abduction.

            On the screen appeared a sequence showing one of the special commandos withdrawing leucocytes from a small and disgustingly healthy strata creature on the other side of the planet. The entry shaft had been in use for several weeks and the motion of the strata creature had caused it to bend in several places, but it was still usable. The corpsmen dropped from the copters and into the sloping tunnel, running and occasionally ducking to avoid the lifting gear which would later haul their catch to the surface. They wore lightweight suits and carried only nets. The leucocytes were their friends. It was very important for them to remember that.

            The leucocytes possessed a highly developed empathic faculty, which allowed them to distinguish the parent body's friends from its foes simply by monitoring their emotional radiation. Provided the corpsmen kidnappers thought warm, friendly thoughts while they went about their business, they were perfectly safe. But it was hard and often frustrating work, netting and hauling and transferring the massive and inert slugs into the transport copters. Sweating and short-tempered as they frequently were, it was not easy to radiate feelings of friendship and helpfulness toward their charges. Circumstances arose in which a corpsman gave way to a flash of anger or irritation-at an item of his own equipment, perhaps- and for such lapses many of them died.

            Rarely did they die singly. At the end of the sequence Conway watched the entire crew of a transport copter taken out within a few minutes, because it had been impossible for one man to think kindly thoughts toward a being who had just killed a crew mate-by injecting a poison which triggered off muscular spasms so violent that the man broke practically every bone in his body-even if his own life did depend on it. There was no protection and no cure. Heavy-duty spacesuits tough enough to resist the needle points of the leeches' probes would not have allowed enough mobility for the corpsmen to do their job, and the creatures killed just as quickly and thoroughly and unthinkingly as they cured.

            "To summarize," said the Chalder as it blanked the screen, "the transfusion and artificial feeding operations are going well at present, but if casualties continue to mount at this rate the supply will fall dangerously short of the computed demand. I therefore recommend, most strongly, that surgery be commenced immediately."

            "I agree," added the Melfan. "Assuming that we must proceed without either the consent or cooperation of the patient, we should start immediately."

            "How immediate?" broke in Captain Williamson, speaking for the first time. "It takes time to deploy a whole sector sub fleet over the operative field. My people will need final briefings and, well, I think the Fleet Commander is a little worried about this one. Up to now his operations have been purely military."

            Conway was silent, trying to force himself to the decision he had been avoiding for several weeks. Once he gave the word to start, once he began cutting on this gargantuan scale, he was committed. There would be no chance to withdraw and try again later, there were no specialists that he could fall back on if the going got tough and, worst of all, there was no time for dithering, because already the patient's condition had been left untreated for far too long.

            "Don't worry, Captain," said Conway, trying hard to radiate the confidence and reassurance which he did not feel. "So far as your people are concerned, this has become a military operation. I know that in the beginning you treated it as a disaster-relief exercise on an unusually large scale, but now it has become indistinguishable from war in your minds, because in war you have to expect casualties and you are certainly getting them. I'm very sorry about that, sir. I never expected such heavy losses and I'm personally very sorry that I taught those tools to glide this morning because that stunt will cost a lot more...

            "It couldn't be helped, Doctor," Williamson broke in, "and one of our people was bound to think of the same idea some time-they've thought of practically everything else. But what I want to know is-"

            "How soon is immediately," said Conway for him. "Well, bearing in mind the fact that the operation will be measured in weeks rather than hours, and provided there are no logistical reasons for holding back, I suggest we start the job at first light on the day after tomorrow."

            Williamson nodded, but hesitated before he spoke. "We can be in position at that time, Doctor, but something else has just come up which may cause you to change your mind about the timing."

            He gestured toward the screen and went on, "I can show you charts and figures, if you like, but it is quicker to tell you the results first. The survey of healthy and less ill strata creatures which you asked our cultural contact people to carry out-your idea being that it might be easier to establish communications with a being who was not in constant pain than otherwise-is now complete. Altogether eighteen hundred and seventy-four sites covering every known strata creature were visited, a tool left unattended on the surface and kept under observation from a distance for periods of up to six hours. Even though the body material was practically identical with that of our patient, including the presence of a somewhat simplified form of eye plant, the results were completely negative. The strata creatures under test made no attempt to control or change the tools in any way, and the small changes which did occur were directly traceable to mental radiation from birds or nonintelligent surface animals. We fed this data to Descartes' computer and then to the tactical computer on Vespasian. The conclusions left no doubt at all, I'm afraid.

            "There is only one intelligent strata creature on Drambo," Williamson ended grimly, "and it is our patient."

            Conway did not reply at once and the meeting became more and more disorganized. To begin with there were a few useful ideas put up-at least, they sounded good until the Captain shot them down. But then instead of ideas he got senseless arguments and bad temper and suddenly Conway knew why.

            They had all been both overworked and overtired when the meeting had started, and that had been five hours ago. The Melfan's bony underside was sagging to within a few inches of the deck. The Hudlar was probably hungry because the water inside the hold had been cleared of all edible material as had the floor, which would similarly displease the constantly rolling Drambon. Above them the enormous Chalder had been hanging in a cramped position for far too long, and the other Earth humans must have been finding their pressure suits as irksome as Conway was finding his. It was obvious that there would be no more useful contributions from anyone at this meeting, including himself, and it was time to wind it up.

            He signaled for silence, then said, "Thank you, everyone. The news that our patient is the planet's only intelligent strata creature makes it necessary for us to try even harder, if that is possible, to make the forthcoming operation a success. It is not a valid reason for delaying surgery.

            "You will all have plenty to occupy you tomorrow," he ended. "I shall spend the time making one last try at obtaining the consent and cooperation of our patient."

            Modifications had been completed to a pair of the tracked boring machines just three days earlier, making them as foolproof as possible and extending their two-way vision equipment to allow Conway to view and, if necessary, direct the operation from anywhere on or inside the strata creature. It was the communications gear that he checked first.

            "I have no intention of becoming a dead hero," Conway explained, grinning. "If we are in any danger I shall be the first to scream for help."

            Harrison shook his head. "The second."

            "Ladies first," said Murchison firmly.

            They drove inland to a healthy area thickly covered by eye plants and stopped for a full hour, then moved on for an hour and stopped again. They spent the morning and early afternoon moving and stopping with no discernible reaction from the patient. Sometimes they drove around in tight circles in an attempt to attract attention, still without success. Not a single tool appeared. Their ground sensors gave no sign that anything was trying to undercut them. Altogether it was turning out to be an intensely frustrating if physically restful day.

            When darkness fell they switched on the digger's spotlights and played them around and watched thousands of eye plants open and close suddenly to this artificial sunshine, but still the strata creature refused the bait.

            "In the beginning the brute must have been curious about us," said Conway, "and anxious to investigate any strange object or occurrence. Now it is simply frightened and hostile, and there are much better targets elsewhere."

            The digger's vision screens showed several transfusion and feeding sites under constant tool attack, and too many dark stains on the ground which were not of oil.

            "I still think," said Conway seriously, "that if we could get close to its brain, or even into the area where the tools are produced, we would stand a better chance of communicating directly. If direct communication is impossible we might be able to artificially stimulate certain sections to make it think that large objects had landed on the surface, forcing it to draw off the tools attacking the transfusion installations. Or if we could gain an understanding of its technology that might give us a lever..."

            He broke off as Murchison shook her head. She produced a chart comprising thirty or more transparent overlays which showed the patient's interior layout as accurately as six months' hard work with insufficient facilities could make it. Her features fell into their lecturing expression, the one which said that she wanted attention but not admiration.

            She said, "We have already tried to find the patient's brain location by backtracking along the nerve paths-that is, the network of rootlets containing metallic salts which are capable of carrying electrochemical impulses. Using test bores taken at random on the top surface and by direct observation from diggers, we found that they link up, not to a central brain, but to a flat layer of similar rootlets lying just above the subsurface. They do not join directly onto this new network, but lie alongside, paralleling it close enough for impulses to be passed across by induction.

            "Some of this network is probably responsible for the subsurface muscular contractions which gave the patient mobility before it took over this particular land mass and stopped climbing over and smothering its enemies, and it is natural to assume that the eye plants above and the muscles below has a direct connection since they would give the first warning of another strata creature attempting to slip over this one, and the subsequent muscular reaction would be almost involuntary.

            "But there are many other root networks in that layer," she went on, "whose function we do not know. They are not color coded-they all look exactly the same except for minute variations in thickness. The type which apparently abstracts minerals from the subsurface rock can vary in thickness. So I would advise against artificial stimulation of any kind. You could very easily start a bunch of subsurface muscles to twitching, and the corpsmen up top would have localized earthquakes to contend with as well as everything else."

            "All right," said Conway irked for no other reason than that her objections were valid. "But I still want to get close to its brain or to the tool-producing area, and if it won't pull us in we must go looking for it. But we're running out of time. Where, in your opinion, is the best place to look?"

            She was thoughtful for a moment, then said, "Either the brain or the tool-producing area could be in a hollow or small valley in the subsurface where, presumably, the creature absorbs necessary minerals. There is a large, rocky hollow fifteen miles away, just here, which would give the necessary protection from below and from all sides while the mass of the overlaying body would save it from injury from above. But there are dozens of other sites just as good. Oh, yes, there would have to be a constant supply of nutriment and oxygen available, but as this is a quasi vegetable process in the patient with water instead of blood as the working fluid, there should be no problem in supplying a deeply buried brain..

            She broke off, her face and jaw stiffening in a successfully stifled yawn. Before she could go on, Conway said, "It's quite a problem. Why don't you sleep on it?"

            Suddenly she laughed. "I am. Hadn't you noticed?"

            Conway smiled and said, "Seriously, I would like to call a copter to pick you up before we go under. I've no idea what to expect if we do find what we're looking for-we might find ourselves caught in an underground blast furnace or paralyzed by the brain's mental radiation. I realize that your curiosity is strong and entirely professional, but I would much prefer that you didn't come. After all, scientific curiosity kills more cats than any other kind."

            "With respect, Doctor," said Murchison, showing very little of it, "you are talking rubbish. There have been no indications of unusually high temperatures on the subsurface, and we both know that while some e-ts communicate telepathically, they can only do so among their own species. The tools are an entirely different matter, an inert but thought-malleable fabrication which. . ." She broke off, took a deep breath and ended quietly, "There is another digger just like this one. I'm sure there would also be an officer and gentleman on Descartes willing to trail you in it."

            Harrison sighed loudly and said, "Don't be antisocial, Doctor. If you can't beat 'em, let them join you."

            "I'll drive for a while," said Conway, treating incipient mutiny in the only way he could in the circumstances, by ignoring it. "I'm hungry, and it's your turn to dish up."

            "I'll help you, Lieutenant," said Murchison.

            As Harrison turned over the driving position to Conway and headed for the galley, he muttered, "You know, Doctor, sometimes I enjoy drooling over a hot dish, especially yours."

            It was shortly before midnight that they reached the area of the subsurface depression, nosed over and bored in. Murchison stared through the direct-vision port beside her, occasionally making notes about the tracery of fine roots which ran through the damp, cork-like material which was the flesh of the strata creature. There was no indication of a conventional blood supply, nothing to show that the creature had ever been alive in the animal rather than the vegetable sense.

            Suddenly they broke through the roof of a stomach and drifted down between the great vegetable pillars which raised and lowered the roof, drawing food-bearing water from the sea and expelling, many days later, the waste material not already absorbed by specialist plants. The vegetable stalactites stretched away to the limits of the spotlight in all directions, each one covered with the other specialized growths whose secretions caused the pillars to stiffen when the stomach had been empty for too long and relax when it was full. Other caverns, smaller and spaced closer together than the stomachs, simply kept the water flowing in the system without performing any digestive function.

            Just before they drifted to the floor Harrison angled the digger into diving position and spun the forward cutters to maximum speed. They struck the stomach floor softly and kept on going. Half an hour later they were thrown forward against their straps. The soft thudding of the cutter blades had risen to an ear-piercing shriek, which died into silence as Harrison switched them off.

            "Either we've reached the subsurface," he said dryly, "or this beastie has a very hard heart.

            They withdrew a short distance, then flattened their angle of descent so that they could continue tunneling with their tracks rolling over the rocky subsurface and the cutters chewing through material which now had the appearance of heavily compressed and thickly veined cork. When they had gone a few hundred yards Conway signaled the Lieutenant to stop.

            "This doesn't look like the stuff that brains are made of," Conway said, "but I suppose we should take a closer look."

            They were able to collect a few specimens and to look closely, but not for long. By the time they had sealed their suits and exited through the rear hatch, the tunnel they had made was already sagging dangerously and, where the wet, gritty floor met the tunnel sides, an oily black liquid oozed out and climbed steadily until it was over their ankles. Conway did not want to take too much of the stuff back with them into the digger. From the earlier samples taken by drill they knew that it stank to high heaven.

            When they were back inside Murchison lifted one of the specimens. It looked a little like an Earthly onion which had been cut laterally in two. The flat underside was covered by a pad of stubby, worm-like growths and the single stalk divided and subdivided many times before joining the nerve network a short distance above them. She said, "I would say that the plant's secretions dissolve and absorb minerals and/or chemicals from the subsurface rock and soil and, with the water which filters down here, provides the lubrication which allows the creature to change position if the mineral supply runs out. But there are no signs of unusual or concentrated nerve networks here, nor are there any traces of the scars which tools leave when they cut their way through this material. I'm afraid we'll have to try again somewhere else."

            Nearly an hour went by before they reached the second hollow and another three took them to the third. Conway had been a little doubtful from the beginning about the third site because it was too close to the periphery, in his opinion, to house a brain. But the possibility had still not been ruled out, on a creature this size, of multiple brains or at least a number of neural substations. She reminded him that the old-time brontosaurus had needed two, and it had been microscopic when compared with their patient.

            The third site was also very close to the beginning of the first incision line.

            "We could spend the rest of our lives searching hollows and still not find what we're looking for," said Conway angrily, "and we haven't that much time."

            His repeater screens showed the sky lightening far above them, with Monitor heavy cruisers already in position, floodlights being switched off at transfusion and feeding installations and occasionally glimpses of Edwards, who had been transferred to the flagship Vespasian as medical liaison chief for the duration. It was his job to translate Conway's medical instructions into military maneuvers for the fleet's executive officers.

            "Your test bores," said Conway suddenly. "I assume they were spaced out at regular intervals and went right down to the subsurface? Was there any indication that the black goo which the patient uses as a lubricant is more prevalent in certain areas than in others? I'm trying to find a section of the creature which is virtually incapable of movement, because-"

            "Of course," said Murchison excitedly, "that is the big factor which makes our intelligent patient different from all the smaller and nonintelligent strata creatures. For better protection the brain, and probably the tool-production centers, would almost certainly have to be in a stationary section. Offhand, I can only remember about a dozen test bores in which lubricant was absent or present in very small quantities, but I can look up the map references for you in a few minutes."

            "You know," said Conway with feeling, "I still don't want you here but I'm glad you've come.

            "Thank you," she said, then added, "I think."

            Five minutes later she had all the available information. "The subsurface forms a small plain ringed by low mountains in that area. Aerial sensors tell us that it is unusually rich in minerals, but then so is most of the center of this land mass. Our test bores were very widely spaced, so that we could easily have missed picking up brain material, but I'm pretty sure now that it is there."

            Conway nodded, then said, "Harrison, that will be the next stop. But it's too far to go traveling on or under the surface. Take us topside and arrange for a transport copter to lift us to the spot. And on the way would you mind angling us toward Throat Tunnel Forty-three, as close to the incision line as you can manage, so that I can see how the patient reacts to the early stages of the operation. It is bound to have some natural defense against gross physical injury.

            He broke off, his mood swinging suddenly from high excitement to deepest gloom. He said, "Dammit, I wish I had concentrated on the tools from the very beginning, instead of getting sidetracked with the rollers, and then thinking that those overgrown leucocytes were the intelligent tool users. I've wasted far too much time."

            "We're not wasting time now," said Harrison, and pointed toward his repeater screens.

            For better or for worse, major surgery had begun.

            The main screen showed a line of heavy cruisers playing ponderous follow-the-leader along the first section of the incision, rattlers probing deep while their pressers held the edges of the wound apart to allow deeper penetration by the next ship in line. Like all of the Emperor class ships they were capable of delivering a wide variety of frightfulness in very accurately metered doses, from putting a few streets full of rioters to sleep to dispensing atomic annihilation on a continental scale. The Monitor Corps rarely allowed any situation to deteriorate to the point where the use of mass destruction weapons became the only solution, but they kept them as a big and potent stick-like most policemen, the Federation's law-enforcement arm knew that an undrawn baton had better and more long-lasting effects than one that was too busy cracking skulls. But their most effective and versatile close-range weapon-versatile because it served equally well either as a sword or a plowshare-was the rattler.

            A development of the artificial gravity system which compensated for the killing accelerations used by Federation spaceships, and of the repulsion screen which gave protection against meteorites or which allowed a vessel with sufficient power reserves to hover above a planetary surface like an old-time dirigible airship, the rattler beam simply pushed and pulled, violently, with a force of up to one hundred Gs, several times a minute.

            It was very rarely that the corps were forced to use their rattlers in anger-normally the fire-control officers had to be satisfied with using them to clear and cultivate rough ground for newly established colonies- and for the optimum effect the focus had to be really tight. But even a diffuse beam could be devastating, especially on a small target like a scout ship. Instead of tearing off large sections of hull plating and making metallic mincemeat of the underlying structure, it shook the whole ship until the men inside rattled.

            On this operation, however, the focus was very tight and the range known to the last inch.

            Visually it was not at all spectacular. Each cruiser had three rattler batteries which could be brought to bear, but they pushed and pulled so rapidly that the surface seemed hardly to be disturbed. Only the relatively gentle tractor beams positioned between the rattlers seemed to be doing anything-they pulled up the narrow wedge of material and shredded vegetation so that the next rattler in line could deepen the incision. It would not be until the incision had penetrated to the subsurface and extended for several miles that the other squadrons still hanging in orbit would come in to widen the cut into what they all hoped would be a trench wide enough to check the spread of vegetable infection from the excised and decomposing dead material.

            As a background to the pictures Conway could hear the clipped voices of the ordnance officers reporting in. There seemed to be hundreds of them, all saying the same things in the fewest possible words. At irregular intervals a quiet, unhurried voice would break in, directing, approving, coordinating the overall effort-the voice of God, sometimes known as Fleet Commander Dermod, the ranking Monitor Corps officer of Galactic Sector Twelve and as such the tactical director of more than three thousand major fleet units, supply and communications vessels, support bases, ship production lines and the vast number of beings, Earth-human and otherwise, who manned them.

            If the operation came unstuck, Conway certainly would not be able to complain about the quality of the help. He began to feel quietly pleased with the way thing were going.

            The feeling lasted for all of ten minutes, during which time the incision line passed through the tunnel-Number Forty-three-which they had just entered. Conway could actually see the inward end of the seal, a thick, corrugated sausage of tough plastic inflated to fifty pounds per square inch which pressed against the tunnel walls. Special arrangements had been needed to guard against loss of working fluid because the strata creature's healing processes were woefully slow. Its blood was quite literally water and one important quality which water did not have was the ability to coagulate.

            Two corpsmen and a Melfan medic were on guard beside the seal. They seemed to be agitated, but there were so many leucocytes moving about the tunnel that he could not see the reason for it. His screens showed the incision line crossing the throat tunnel. A few hundreds of gallons of water between the seal and the incision poured away-considering the size of the patient, it was scarcely a drop. The rattlers and tractors moved on, extending and deepening the cut while the great immaterial presser beams, the invisible stilts which supported the enormous weight of the cruisers, pushed the edges apart until the incision became a widening and deepening ravine. A small charge of chemical explosive brought down the roof of the emptied section of tunnel, reinforcing the plastic seal. Everything seemed to be working exactly as planned, until the immediate attention signal began flashing on his board and Major Edwards' face filled the screen.

            "Conway," said the Major urgently. "The seal in Tunnel Forty-three is under attack by tools."

            "But that's impossible," said Murchison, in the scandalized tones of one who has caught a friend cheating at cards. "The patient has never interfered with our internal operations. There are no eye plants down here to give away our positions, no light to speak of, and the seal isn't even metal. They never attack plastic material on the surface, just men and machines."

            "And they attack men because we betray our presence by trying to take mental control of them," Conway said quickly. Then to Edwards, "Major, get those people away from the seal and into the supply shaft. Quickly. I can't talk to them directly. While they're doing that tell them to try not to think-"

            He broke off as the seal ahead disappeared in a soft white explosion of bubbles which roared toward them along the tunnel roof. He could not see anything outside the digger and inside only Edwards' face and pictures of ships in line astern formation.

            "Doctor, the seal's gone," shouted the Major, his eyes sliding to one side. "The debris behind the seal is being washed away. Harrison, dig in!"

            But the Lieutenant could not dig in because the bubbles roaring past made it impossible to see. He threw the tracks into reverse, but the current sweeping them along was so strong that the digger was just barely in contact with the floor. He killed the floodlights because reflection from the froth outside the canopy was dazzling them. But there was still a patch of light ahead, growing steadily larger...

"Edwards, cut the rattlers. . .

            A few seconds later they were swept out of the tunnel as part of a cataract which tumbled down an organic cliff into a ravine which seemed to have no bottom. The vehicle did not explode into its component parts nor themselves into strawberry jam, so they knew that Major Edwards had been able to kill the rattler batteries in time. When they crashed to a halt a subjective eternity later, two of the repeater screens died in spectacular implosions and the cataract which had cushioned their fall on the way down began battering at their side, pushing and rolling them along the floor of the incision.

            "Anyone hurt?" said Conway.

            Murchison eased her safety webbing and winced. "I'm black and blue and.., and embossed all over."

            "That," said Harrison in an obviously uninjured tone, "I would like to see.

            Both relieved and irritated, Conway said, "First we should look at the patient."

            The only operable view screen was transmitting a picture taken from one of the copters stationed above the incision. The heavy cruisers had drawn off a short distance to leave the operative field clear for rescue and observation copters, which buzzed and dipped above the wound like great metal flies. Thousands of gallons of water were pouring from the severed throat tunnel every minute, carrying the bodies of leucocytes, farmer fish, incompletely digested food and clumps of vital internal vegetation into and along the ravine. Conway signaled for Edwards.

            "We're safe," he said before the other could speak, "but this is a mess. Unless we can stop this loss of fluid, the stomach system will collapse and we will have killed instead of cured our patient. Dammit, why doesn't it have some method of protecting itself against gross physical injury, a nonreturn valve arrangement or some such? I certainly did not expect this to happen..

            Conway checked himself, realizing that he was beginning to whine and make excuses instead of issuing instructions. Briskly, he said, "I need expert advice. Have you a specialist in short-range, low-power explosive weapons?"

            "Right," said Edwards. A few seconds later a new voice said, "Ordnance control, Vespasian, Major Holroyd. Can I help you, Doctor?"

            I sincerely hope so, thought Conway, while aloud he went onto outline his problem.

            They were faced with the emergency situation of a patient bleeding to death on the table. Whether the being concerned was large or small, whether its body fluid was Earth-human blood, the superheated liquid metal used by the TLTUs of Threcald Five or the somewhat impure water which carried food and specialized internal organisms to the far flung extremities of this Drambon strata creature's body, the result would be the same-steadily reducing blood pressure, increasingly deep shock, spreading muscular paralysis and death.

            Normal procedure in these circumstances would be to control the bleeding by tying off the damaged blood vessel and suturing the wound. But this particular vessel was a tunnel with walls no more strong or elastic than the surrounding body material, so they could not be tied or even clamped. As Conway saw it the only method remaining was to plug the ruptured vessel by bringing down the tunnel roof.

            "Close-range TR-7s," said the ordnance officer quickly. "They are aerodynamically clean, so there will be no problem shooting into the flow, and provided there are no sharp bends near the mouth of the tunnel any desired penetration can be achieved by-"

            "No," said Conway firmly. "I'm concerned about the compression effects of a large explosion in the tunnel itself. The shock wave would be transmitted deep into the interior, and a great many farmer fish and leucocytes would die, not to mention large quantities of the fragile internal vegetation. We must seal the tunnel as close to the incision as possible, Major, and confine the damage to that area.

            "Armor-piercing B-22s, then," said Holroyd promptly. "In this material we could get penetrations of fifty yards without any trouble. I suggest a simultaneous launch of three missiles, spaced vertically above the tunnel mouth so that they will bring down enough loose material to block the tunnel even against the pressure of water trying to push it away as it subsides."

            "Now," said Conway, "you're talking."

            But Vespasian's ordnance officer could do more than talk. Within a very few minutes the screen showed the cruiser hovering low over the incision. Conway did not see the missiles launched because he had suddenly remembered to check if their digger had been swept far enough to avoid being buried in the debris, which fortunately it had. His first indication that anything at all had happened was when the flow of water turned suddenly muddy, slowed to a trickle and stopped. A few minutes later great gobs of thick, viscous mud began to ooze over the lip of the tunnel and suddenly a wide area around the mouth began to sag, fall apart and slip like a mass of brown porridge into the ravine.

            The tunnel mouth was now six times larger than it had been and the patient continued to bleed with undiminished force.

            "Sorry, Doctor," said Holroyd. "Shall I repeat the dose and try for greater penetration?"

            "No, wait."

            Conway tried desperately to think. I knew that he was conducting a surgical operation, but he did not really believe it-both the problem and the patient were too big. If an Earth-human was in the same condition, even if no instruments or medication were available, he would know what to do-check the flow at a pressure point, apply a tourniquet.. . That was it.

            "Holroyd, plant three more in the same position and depth as last time," he said quickly. "But before you launch them can you arrange your vessel's presser beams so that as many of them as possible will be focused just above the tunnel opening? Angle them against the face of the incision instead of having them acting vertically, if possible. The idea is to use the weight of your ship to compress and support the material brought down by the missiles."

            "Can do, Doctor."

            It took less than fifteen minutes for Vespasian to rearrange and refocus her invisible feet and launch the missiles, but almost at once the cataract ceased and this time it did not resume. The tunnel opening was gone and in its place there was a great, saucer-shaped depression in the wall of the incision where Vespasian's starboard pressers were focused. Water still oozed through the compacted seal, but it would hold so long as the cruiser maintained position and leaned her not inconsiderable weight on it. As extra insurance another inflatable seal was already being moved into the supply tunnel.

            Suddenly the picture was replaced by that of a lined, young-old face above green-clad shoulders on which there rested a quietly impressive weight of insignia. It was the Fleet Commander himself.

            "Doctor Conway. My flagship has engaged in some odd exercises in her time, but never before have we been asked to hold a tourniquet."

            "I'm sorry, sir-it seemed the only way of handling the situation. But right now, if you don't mind, I'd like you to have this digger lifted to map reference numbers..

            He broke off because Harrison was waving at him. The Lieutenant said softly, "Not this digger. Ask him to have the other one checked out and waiting when they get around to pulling us out."

            Three hours later they were in the second modified and strengthened digger, suspended under a transport copter and approaching the area which, they hoped, contained the strata creature's brain and/or tool producing facilities. The trip gave them a chance to do some constructive theorizing about their patient.

            They were now convinced that it had evolved originally from a mobile vegetable form. It had always been large and omnivorous, and when these life-forms began to live off each other they grew in size and complexity and shrank in numbers. There did not seem to be any way that the strata creature could reproduce itself. It simply continued to live and grow until one of its own kind who was bigger than it was killed it. Their patient was the biggest, oldest, toughest and wisest of its kind. As the sole occupant of its land mass for many thousands of years, there had no longer been the necessity for it to move itself bodily and so it had taken root again.

            But this had not been a process of devolution. With no chance of cannibalizing others of its own kind, it devised methods of controlling its growth and of rendering its metabolism more efficient by evolving tools to do the jobs like mining, investigating the subsurface, processing necessary minerals for its nerve network. The original farmer fish were probably a strain which were able to survive, like the legendary Jonah, in its stomach and later grow plant teeth for both the parent creature and the farmer fish to defend themselves against sea predators sucked in by the mouths. How the leucocytes got there was still not clear, but the rollers occasionally ran across a smaller, less highly evolved variety which were probably the leeches' wild cousins.

            "But one point which we must keep in mind when we try to talk to it," Conway ended seriously, "is that the patient is not only blind, deaf and dumb, it has never had another of its own kind to talk to. Our problem isn't simply learning a peculiar and difficult e-t language, we have to communicate with something which does not even know the meaning of the word communicate."

            "If you're trying to raise my morale," said Murchison dryly, "you aren't."

            Conway had been staring ahead through the forward canopy, mostly to avoid having to look at the carnage depicted on his repeater screens where the tool attacks were taking an increasingly heavy toll at the feeding and transfusion sites. He said suddenly, "The suspected brain area is far too extensive to be searched quickly but, correct me if I'm wrong, isn't this also the locality where Descartes made her first touchdown? If that is so then the tools sent to investigate her had a relatively short distance to come, and if it is possible to trace the path of a tool by the scar tissue it leaves in the body material. .

            "It is," said Murchison, looking excited. Harrison gave new instructions to the transport copter's pilot without having to be told and a few minutes later they were down, cutting blades spinning and nosing into their patient's spongy quasi flesh.

            But instead of the large, cylindrical plug cut from the body material they found a flat, reversed conical section which tapered sharply to a narrow, almost hair-thin wound which angled almost at once toward the suspected brain area.

            "The ship would have been drawn only a short distance below the surface, obviously," said Murchison. "Enough to let tools make contact with its total surface while supported by body material, instead of making a fleeting contact after bouncing themselves into the air. But do you notice how the tools, even though they must have been cutting through at top speed, still managed to avoid severing the root network which relays their mental instructions . . .

            "At the present angle of descent," Harrison cut in, "we are about twenty minutes from the subsurface. Sonar readings indicate the presence of caverns or deep pits."

            Before Conway could reply to either of them, Edwards' face flicked onto the main screen. "Doctor, seals Thirty-eight through Forty-one have gone. We're already holding tourniquets at Eighteen, Twenty-six and Forty-three, but-"

            "Same procedure," snapped Conway.

            There was a dull clang followed by metallic scraping sounds running the length of the digger. The sounds were repeated with rapidly increasing frequency. Without looking up, Harrison said, "Tools, Doctor. Dozens of them. They can't build up much impetus coming at us through this spongy stuff and our extra armor should cope. But I'm worried about the antenna housing."

            Before Conway could ask why, Murchison turned from the view port. She said, "I've lost the original trail, Doctor-this area is practically solid with tool scar tissue. Traffic must be very heavy around here."

            The secondary screens were showing logistic displays on the deployment of ships, earth-moving machinery, decontamination equipment and movements into and out of the feeding and transfusion areas, and the main screen showed Vespasian no longer in position above Tunnel Forty-three. It was losing height and wheeling around in a ponderous, lateral spin while its pilot was obviously fighting hard to keep it from flipping over onto its back.

            One of its four presser installations, Conway saw during the next swing, had been smashed in as if by a gigantic hammer and he knew without being told that this was the one which had been holding closed the ruptured Forty-three. As the ship whirled closer to the ground he wanted to close his eyes, but then he saw that the spin was being checked and that the surface vegetation was being flattened by the three remaining pressers, fanned out at maximum power to support the ship's weight.

            Vespasian landed hard but not catastrophically. Another cruiser moved into position above Forty-three while surface transport and copters raced toward the crash-landed ship to give assistance. They arrived at the same time as a large group of tools which were doing nothing at all to help.

            Suddenly Dermod's head filled the screen.

            "Doctor Conway," said the Fleet Commander in a coldly furious voice, "this is not the first time that I have had a ship converted to scrap around me, but I have never learned to enjoy the experience. The accident was caused by trying to balance virtually the whole of the ship's weight on one narrowly focused presser beam, with the result that its supporting structure buckled and damn near wrecked the ship."

            His tone warmed a little, but only temporarily, as he went on, "If we are to hold tourniquets over every tunnel, and with tools attacking every seal it looks as if we will have to do just that, I shall either have to withdraw my ships for major structural modifications or use them for an hour or so at a time and check for incipient structural failure after each spell of duty. But this will tie up a much larger number of ships in unproductive activity, and the farther we extend the incision the more tunnels we will have to sit on and the slower the work will go. The operation is fast becoming a logistical impossibility, the casualty figures and material losses are making it indistinguishable from a full-scale battle, and if I thought that the only result would be the satisfaction of your medical curiosity, Doctor, and that of our cultural contact people, I would throw a permanent 'Hold' on it right now. I have the mind of a policeman, not a soldier-the Federation prefers it that way. I don't glory in this sort of thing...

            The digger lurched and for an instant Conway felt a sensation impossible in these surroundings, that of free fall. Then there was a crash as the vehicle struck rocky ground. It landed on its side, rolled over twice and moved forward again, but skidding and slewing to one side. The sound of tools striking the hull was deafening.

            Two vertical creases appeared on the Fleet Commander's forehead. He said, "Having trouble, Doctor?"

            The constant banging of tools made it hard to think. Conway nodded and said, "I didn't expect the seals to be attacked, but now I realize that the patient is simply trying to defend itself where it thinks it is under the heaviest attack. I also realize now that its sense of touch is not restricted to its top surface. You see, it is blind, deaf and dumb but it seems to be able to feel in three dimensions. The eye plants and subsurface root networks allow it to feel areas of local pressure, but vaguely, without detail. To feel the fine details it sends tools, which are extremely sensitive- sensitive enough to feel the airflow over their wings in the glider configuration and reproduce the shape themselves at will. Our patient learns very quickly and that glider I thought at it has cost a lot of lives. I wish-"

            "Doctor Conway," the Fleet Commander broke in harshly. "You are

either trying to make excuses or giving me a very basic lecture with which

I am already familiar. I have time to listen to neither. We are faced with

a surgical and tactical emergency. I require guidance."

            Conway shook his head violently. He had the feeling that he had just said or thought of something important but he did not know what it was. He had to stay with his present train of thought if he expected to drag it out into the light again.

            He went on, "The patient sees, experiences everything, by touch. So far our only area of common contact are the tools. They are thought controlled extensions of its sense of touch throughout and for a short distance above the patient's body. Our own mental radiation and control are more concentrated and of strictly limited range. The situation has been that of two fencers trying to communicate only through the tips of their foils-"

            He stopped abruptly because he was talking to an empty screen. All three repeaters glowed with power, but there was neither sound nor vision.

            Harrison shouted, "I was afraid of this, Doctor. We strengthened the hull armor but had to cover the antenna housing with a plastic radome to allow two-way communications. The tools have found our weak spot. Now we are deaf, dumb and blind, too-and missing one leg because our port caterpillar tread won't work."

            The digger had come to rest on a flat shelf of rock in a large cavern which angled steeply into the subsurface. Above and behind them hung a great mass of the creature's body material from which there was suspended thousands of rootlets which joined and rejoined until they became thick, silvery cables writhing motionlessly across the cavern floor, walls and roof before disappearing into the depths. Each cable had at least one bud sprouting from it, like a leaf of wrinkled tinfoil. The more well developed buds quivered and were trying to take the shapes of the tools which were attacking the digger.

            "This is one of the places where it makes the tools," she said, using a spotlight as pointer, "or should I say grows them-I still can't decide whether this is an animal or vegetable life-form basically. The nervous system seems to be centered in this area, so it is almost certainly part of the brain as well. And it is sensitive-do you see how carefully the tools avoid those silver cables while they are attacking?"

            "We'll do the same," said Conway, then to Harrison, "That is, if you can move the digger on one track to that overhanging wall with the cables running along it, without crushing those two on the floor?"

            Damage in this sensitive area could have serious effects on their patient.

            The Lieutenant nodded and began rocking the digger forward and backward along the shelf until they were tight against the indicated wall. Protected by the sensitive cables above, the cavern floor below and the rocky wall on their starboard side, the tool attack was confined to their unprotected port side. They could once again hear themselves think, but Harrison pointed out firmly but apologetically that they could not climb the slope or dig their way out on one track, that they could not call for help and that they had air for only fourteen hours and then only if they sealed their suits to use their remaining tanked air.

            "Let's do that now," said Conway briskly, "and move outside. Station yourselves at each end of the digger, under the cables and with your backs to the cavern wall. That way you will have to think off attacks from the front only-any tool trying to cut through the rock behind you will make too much noise to take you by surprise. I also want you far enough from my position amidships so that your mental radiation will not affect the tools which I will be trying to control..

            "I know that smug, self-satisfied look," said Murchison to the Lieutenant as she began sealing her helmet. "Our Doctor has had a sudden rush of brains to the head. I think he intends talking to the patient."

            "What language?" asked Harrison dryly.

            "I suppose," said Conway, smiling to show the confidence which he did not feel, "you could call it three-dimensional Braille."

            Quickly he explained what he hoped to do and a few minutes later they were in position outside the digger. Conway sat with his back to the port track housing a few feet from a water-filled depression in the cavern floor. There was a hole of unknown depth in the center of the depression where a cable or similar ore-extracting plant had eaten its way into the rock. To one side of him a group of seven or eight tools had merged together to encircle and squeeze the vehicle's hull, and some of the armor was beginning to gape at the seams. Conway thought a break in the metal band and then he rolled it into the depression like a great lump of animated, silvery dough. Then he got down to work.

            Conway made no attempt to protect himself against attacking tools. He intended concentrating so hard on one particular shape that anything which came within mental range would, he hoped, lose its dangerous edges or points.

            Thought-shaping the creature's outward aspect was easy. Within a few minutes there was a large, silvery pancake-a small-scale replica of the patient-lying in the center of the pool. But thinking three dimensionally of the mouths and their connecting tunnels and stomachs was not so easy. Even harder was the stage when he began thinking the tiny stomachs into expanding and contracting, sucking the gritty, algae-filled water into his scale model and expelling it again.

            It was a crude, oversimplified model. The best he could manage at one time was eight mouths and connecting stomachs, and he was very much afraid that it bore the same relation to the patient that a doll did to a living baby. But then he began to add the creeping motions he had observed in smaller, younger strata creatures, keeping the area around the central depression motionless, however, and hoping that with the pumping motions of the stomachs he was giving the impression of a living organism. The sweat poured off his forehead and into his eyes, but by then it did not matter that he could not see properly, because the sections he was shaping were out of sight anyway. Then he began to think certain areas solid, motionless, dead. He extended these dead, motionless and detail-less areas until gradually the whole model was a solid, lifeless lump.

            Then he blinked the sweat out of his eyes and started all over again, and then again, and suddenly the others were standing beside him.

            "They aren't attacking us anymore," said Harrison quietly, "and before they change their minds I am going to try fixing that damaged track. At least, there is no shortage of tools."

            Murchison said, "Can I help-apart from keeping my mind blank to avoid warping your model?"

            Without looking up Conway said, "Yes, please. I'm going to take it through the same sequence once again, but halt it at the point where the dead areas extend to at the present time. When I do that I would like you to think the positions of our incisions and extend and widen them while I seal the severed throat tunnels and think the feeding and transfusion shafts. You withdraw the excised material a short distance and think it solid-dead, that is-while I try to get across the idea that the remainder is alive and twitching and likely to stay that way."

            She caught on very quickly but Conway had no way of knowing if their patient had, or could, catch on. Behind them Harrison was at work on the damaged tread while before them their model of the patient and the effects of their present surgery became more and more detailed- right down to the miniature corrugated seals and what happened to the creature when one of them was collapsed. But still there was no indication from the patient that it understood what they were trying to tell it.

            Suddenly Conway stood up and began climbing the sloping floor. He said, "I'm sorry, I have to move out of range for a minute to catch my mental breath."

            "Me, too," she said a few minutes later. "I'll join you.., look!"

            Conway had been staring at the darkness of the cavern roof to rest both his mind and his eyes. He looked down quickly, thinking they were him into the digger and, while Conway made contact with the surface, Murchison instinctively raised her hand in farewell to the cavern and the shapes of the tool models scattered across the shelf. She must have been thinking very hard about her good-bye because her last model raised its hand also and kept it there while the digger crawled slowly out of mental range.

            Suddenly all three repeaters were alive and Dermod was staring at him, his face reflecting concern, relief and excitement in sequence and then altogether. He said, "Doctor, I thought we'd lost you-you blanked out four hours ago. But I can report progress. The incision is proceeding and all tool attacks ceased half an hour ago. There is no tool trouble reported from the tunnel seals, the decontamination teams, the transfusion shafts anywhere. Doctor, is this a temporary condition?"

            Conway let his breath go in a long, loud sigh of relief. Their patient was a very bright lad despite its physically slow reaction times. He shook his head and said, "You will have no more trouble from the tools. In fact, you will find them of assistance in helping maintain equipment and for use in awkward sections of the incision once we make it understand our needs. You can also forget about digging that isolation trench-our patient retains enough mobility to withdraw itself from the newly excised material-which means that ships which would have been tied up in digging that trench will now be free to extend the incision more rapidly, so that our operation will be completed in a fraction of the time originally thought necessary.

            "You see, sir," Conway ended, "we now have the active cooperation of our patient."

            Major surgery was completed in just under four months and Conway was ordered back to Sector General. Postoperative treatment would take a great many years and would proceed in conjunction with the exploration of Drambo and the closer investigation of its life-forms and cultures. Before leaving, while he was still seriously troubled by the thought of the casualty figures, Conway had once questioned the value of what they had done. A rather supercilious cultural contact specialist had tried to make it very simple for him by saying that difference, whether it was cultural, physiological or technological, was immensely valuable. They would learn much from the strata creature and the rollers while they were teaching them. Conway, with some difficulty, accepted that. He could also accept the fact that, as a surgeon, his work on Drambo was done. It was much harder to accept the fact that the pathology team, particularly one member of it, still had a lot of work to do.

            While O'Mara did not openly enjoy his anguish, neither did he display sympathy.

            "Stop suffering so loudly in silence, Conway," said the Chief Psychologist on his return, "and sublimate yourself-preferably in quicklime. But failing that there is always work, and an odd case has just come in which you might like to look at. I'm being polite, of course. It is your case as of now. Observe."

            The large visi screen behind O'Mara's desk came to life and he went on. "This beastie was found in one of the hitherto unexplored regions, the victim of an accident which virtually cut its ship and itself in two. Airtight bulkheads sealed off the undamaged section and your patient was able to withdraw itself, or some of itself, before they closed. It was a large ship, filled with some kind of nutrient earth, and the victim is still alive- or should I say half alive. You see, we don't know which half of it we rescued. Well?"

            Conway stared at the screen, already devising methods of immobilizing a section of the patient for examination and treatment, of synthesizing supplies of that nutrient soil which now must be virtually sucked dry, and for studying the wreck's controls to gain data on its sensory equipment. If the accident which had wrecked its ship had been due to an explosion in the power plant, which was likely, then this might well be the front half containing the brain.

            His new patient was not quite the Midgard Serpent but it did not fall far short of it. Twisting and coiling it practically filled the enormous hangar deck which had been emptied to accommodate it.

            "Well?" said O'Mara again.

            Conway stood up. Before turning to go he grinned and said, "Small, isn't it?"