The airless streets were filled with space-suited tourists from the tree these days. They gawked at the massive excavated buildings, hunted for souvenirs in the rubble, and generally got in the archaeologists’ way. About a quarter of the population could be found on the surface of the diskworld at any given time, and the proportion was increasing as quickly as pressurized accommodations could be provided and atmosphere plants cloned.

Bram strolled down the broad, roughed-out avenue with Mim at his side, trying to keep his feet on the ground and rubbernecking like anybody else. A lot had been accomplished since his last visit; duties aboard the tree had kept him busy there for several Tendays. The tops of more buildings had emerged from the gray dust, and the tallest of them now stood at a height of twenty feet or more.

“It's coming to life again,” Mim said, reading his thoughts. “You can almost imagine what it must have been like."

“Hundreds of thousands of people going about their business—more than ever existed on the Father World, let alone gathered in one place,” Bram agreed. “We've found shops, theaters, even a sports arena where they played a game in midair with a ball and stick, and you were out of bounds when your feet touched the ground. And we've only begun to dig."

Mim said wonderingly. “So many! As many as the Nar! And it looks crowded to me with only a few thousand here!"

“Most of the shirt-sleeve traffic between buildings would have been through the tunnel system. Still, it must have been pretty lively on the surface."

Two space-suited people walked by, bearing a huge slab of granite that seemed to be covered with bas-reliefs. They were walking almost normally, thanks to the tons of mass that kept their boots pressed to the ground. One of them freed an arm to wave at Bram and Mim as they passed. The slab dipped, but the person caught it before it floated too far down out of its inertial path.

Bram waved back, frowning within his helmet. “I wonder where they got that,” he said. “They're supposed to leave things in place till an archaeologist can have a look at the site. There are too many helpful amateurs wandering around."

“Does it matter?"

“Very much, apparently. Ame says that the way finds are sited tells them as much as the finds themselves. And with bones especially, there's a question of missing pieces."

“Those long-footed skeletons?"

“She's got some fairly complete ones. There's a question about the dating. She sent word that there's something she wants to discuss with me."

“And lots of Cuddly bones?"

“Yes, and some they can't identify. She thinks that they may have been pets of Original Man."

Mim gave a subdued shudder and linked arms with Bram. “Ugh—bones! Still, it makes a good excuse for an excursion. The view gets more spectacular all the time."

They both looked toward the horizon at the half-risen disk. It was a swollen red orb that stretched across most of the sky, its oblique angle squashing it out of shape. A smaller disk, back-to, made a black shadow across the glowing field. With the overhead moon brightening up, the diskworld was a reasonably well lit place these days—about on a par with the Father World nights when the lesser sun had been in the sky.

They had been in the system long enough for the diskworld's rotation to bring this segment of the rim down almost to the plane of orbit. Yggdrasil, after some complicated maneuvering, was about a quarter diameter behind them again and catching up fast. At present, the trip from the tree took eleven days, the trip back even longer, but that didn't stop the excursionists. With Yggdrasil renewed and the crust of the diskworld itself to tap, there was fuel literally to burn.

They continued their shuffling stroll. A Cuddly popped up out of a hole in the ground in front of them, sat up on its haunches, and gave them a fearless, big-eyed stare. The little animals had quickly allowed their natural curiosity to overtake their initial caution of human beings, and now they were all over the place.

Mim gave a cry of delight. “Aren't they cute? Look at those clever little paws! They're almost human! Can we take one back with us?"

“Why not? Half the people on the tree seem to have adopted a Cuddly. Or vice versa. They're easy to tame, they eat anything, and they're nice to have around."

There had been some fear at first that the little burrowing beasts would spread uncontrolled through Yggdrasil's vessels and passageways and perhaps interfere with the tree's internal ecology. But that hadn't been the case. The Cuddlies seemed to prefer human company, and they hung around the living quarters, attaching themselves to a particular person or family. They were affectionate little things, rubbing against a person's leg until picked up and stroked, or even forcing matters by climbing up themselves to an arm or a shoulder. They were also shameless little beggars. Few people could resist them. They had quickly discovered all the outside exits, and during Yggdrasil's “night” they liked to prowl about in naked space, among the leaves and branches. They could go an hour or more without breathing, living off the compressed oxygen in their accessory lungs or trapped in their amazing fur with its overlapping erectile follicles.

“Oh, look, I think it's begging for food,” Mim exclaimed. “Do you have anything with you?"

“Afraid not. I had half a cornwich in one of my seal-pockets, left over from the shuttle snack bin, but I threw it away when we helmeted up."

The big-eyed little furball, its coat fluffed out for vacuum, was balancing itself on one foot and its tail, holding out its right paw and right foot in tandem, like a pair of tiny human hands. It held the pose for a long moment, decided that Bram and Mim weren't worth bothering with, and scooted off to find a better prospect.

“Oh!” Mim said, disappointed. “What are they, Bram? Were they brought here by Original Man?"

“Ame doesn't think so. They're too recent. She's found the bones of what seems to be a transitional form they may have evolved from—and that only goes back about twenty million years. Before that, there's a gap. All we know so far is that they have terrestrial DNA."

The avenue they were walking along was one of the spokes of the great circular plaza that centered on the moon ladder—the initial dig had started here, and so far about a square mile of the surrounding city had been dug up. Now, as Bram and Mim emerged into the open spaces of the plaza, they both looked up.

A climber was coming down from the moon, an angular leggy shape that was silhouetted against the eerie red glow of the rising disk. As they watched, the artificial creature detoured around the stalled moon car, stepping carefully over the smooth surface and finding a foothold on the rope below. The climber was wearing a transparent ten-legged space suit that had been designed by, of all people, Marg; it included an extra tuck of material that fit over the passenger cup and billowed out to provide a habitable bubble for the five-hour climb.

“They've found Cuddlies on the moon, too,” Bram said. “Whole colonies of them. They've been established there for millions of years—and apparently they still travel back and forth. We've found fresh footprints around the rope. How they do it is a mystery. Even with a stop at the turnover station. Young Jorv thinks they have some way of taking extra air along, but that seems farfetched, clever little beasts though they are.” He gave a wide grin. “Of course, now they're spoiled—they hitch rides with us in the climbers."

“Are they digging up there, too?"

“Yes. We've found the remains of some tremendous engineering structures—extrusion devices on a scale that can hardly be imagined. Evidently, the original engineers played out the supporting filament from both ends when they were manufacturing this world."

“So Ang told me. Jao can hardly contain himself now that his theory of suspension construction's been vindicated."

“We're trying to verify it at this end, too. We've sunk several shafts at a slant and found that the moonrope extends as far down as we're able to reach. We've gone past the crust now—it's easy with digging machines in this low gravity—and penetrated through to the foamed understructure. We have to proceed carefully, though, to avoid disturbing the Cuddly burrows. They're thick in the vicinity of the rope—it seems to be a main travel route downward. When the excavators started, they burst some of the bubbles and let the air out."

“Oh, Bram, did they—"

“Relax. You can't kill a Cuddly by taking away its air—they had plenty of time to squeeze through their little tunnels to the adjoining cavities. We messed up their gardens, though, No wonder the little rascals are such beggars."

“Gardens?"

“Yes, we've uncovered a whole ecology down there. Jorv thinks that the ancestors of the Cuddlies carried seeds back from their surface foraging expeditions to the old granaries and warehouses of Original Man. Buried the seeds in their dens or excreted them—and some were still viable enough to sprout. Millions of years of evolution would have done the rest. And they would have carried bacteria, fungus spores—even algae—too. There's insect life down there as well, marvelously adapted to the environment."

“How can things grow in the dark?"

“There's no visible light, true, except for bioluminescence. But the whole interior of the diskworld is suffused with infrared because of its energy-trapping structure, and the plant life's learned to use it. For that matter, the Cuddlies themselves see quite well in the far red. Jorv suspects that the Cuddlies may even take a hand in cultivating some of the edible plants. That's not unheard of in the animal kingdom. Something called an ant once did it—grew a fungus crop in its nest. Planted it, fertilized it, even chewed leaves to mulch it."

“Could the Cuddlies be that smart?"

“It would be instinctual behavior. A survival characteristic developed through the ages. Mim, we're finding out so much about terrestrial life from the books and microrecords in the libraries we've unearthed and from studying the organisms in the Cuddly burrows. Earth must have been a wonderful place! There were flying things that wove nests, rodents that built dams! Animal societies that cared for their young cooperatively! And we're a part of that richness and diversity!"

She reached for his gloved hand and gave it a clumsy squeeze. “I know. Life will never be the same again.” She darted a a mischievous glance at him. “The food, for one thing. Marg's been experimenting with some of those frozen seeds that were found in storage. She says we'll soon be eating something called an artichoke."

Bram laughed. “She'll have us eating King James's forbidden fruit next."

“We already are,” Mim said quite seriously. “Wasn't that the fruit of the tree of knowledge?"

Bram sobered. “More knowledge than we can absorb during our stay here. We'll have to come back someday, Mim, after we find our world and get settled.” He took her by the arm. “Come on, we'd better find Ame and find out what she has to tell us."

The archaeologists had chosen the big sports arena as their headquarters. It was the only place large enough to reassemble some of their finds. Most of it was still underground, a tall interior space that the diggers had gained access to after excavating only a couple of layers.

Bram and Mim followed the vehicle ramp downward to a domed receiving area where several of the monstrous Nar digging machines were parked awaiting service and a number of heavy-duty walkers were being carefully unloaded under supervision. A driver going off duty let them in through one of the small prefabricated personnel locks that had been ferried down from the tree and installed here.

The living quarters were a careless jumble of plastic cubicles around the perimeter of the dig. Bram and Mim gratefully accepted an offer of showers and fresh tunics before going on through to the huge cylindrical cavity proper; several hours in a space suit doesn't do much to make a person presentable.

Banks of powerful lamps had been mounted far overhead as work lights. In their harsh glare, the cavernous interior took on a stark pattern of bright surfaces outlined by black shadow. Small groups of people in smocks or tabards were scattered across the immense broken floor, working at some of the hundreds of long tables where fragments of artifacts were being sorted and cataloged. More treasures were on display along the tiers of former spectator balconies in arrangements that made sense to the various specialists.

The larger reconstructions, some of them fairly complete, rose at intervals from the floor. Bram saw an articulated eight-wheeled surface vehicle taking shape—a series of portholed balls connected by flexible access tubes—and a towering plinth with the legs of a colossal metal statue still attached to it. Elsewhere, a section of wall with an engraved gate was being put together from a pile of stone blocks.

Bram pointed upward. “You can see where we patched the roof to pressurize the place—and we only had to do that because we broke through it ourselves. Otherwise, we only had to put in a few minor seals to make the place airtight again. They built well, these former humans. The supporting walls were fused stone and carbon, yards thick."

“What kind of games did they play here?"

“We've found clues to that in some bas-reliefs we dug up. One game was played with a ball and paddles. You struck the ball with a paddle or kicked it with a foot while flapping the paddles to try to stay aloft as long as possible. There was a variation played only with a stick—the players dropped faster, and the plays were shorter. If you'll look way up toward the ceiling past the lights, you'll see the remnants of the drop grid. At the beginning of each play the teams were released simultaneously at a signal, in their starting positions."

They continued threading their way between the tables across the wide floor. Progress was tricky because the floor was not smooth enough for a low-gravity scuff, and there was a tendency to bounce too high when surmounting some block of rubble—but they couldn't sail over the obstacles, either, because they had to be careful of the tables.

“They drank out of strange cups,” Mim said, pausing at a table spread with shards of plastic ware.

Bram examined one of the more complete cups, a two-handled affair whose top tapered into a sort of spout that one could put into one's mouth, almost like a nipple.

“Actually, that's not such a bad design for a low-gravity environment. Prevents sloshing. Better than our own lidded cups,” Bram observed.

“That's not what I meant. It's the handles. They don't seem to fit the hand very well. I'd find it very awkward to drink from one."

Instead of being designed for one or two fingers and an opposing thumb, the handles were fat knobs with five vertical grooves. Bram could see what Mim meant. If one were going to hold a cup with two hands as if it were a bowl, the natural tendency would be to cradle it laterally, in the direction the wrists faced. If handles were needed at all, the grooves ought to have been horizontal—and there ought to have been only four of them, with a depression for the thumb on the opposite side.

“Maybe their wrists were more supple than ours,” he said. He smiled at a sudden comic image. “Or maybe they had no elbow room at their tables."

“I'm serious."

“So am I. About the wrist joints, anyway. Mim, what if Original Man didn't become extinct seventy-odd million years ago, as we've always thought? What if he evolved past us—past the image of himself that he transmitted to the Virgo cluster?"

“Have you talked to Edard about the musical instruments?"

“What? No, Edard leads his own life these days. I haven't seen him for a ten of Tendays."

“They put him on one of the evaluation committees. Asked for his thoughts on fragments that seemed to belong to musical instruments. There's a sort of pottery ... flute, I'd guess you'd call it, in the shape of a tapered ovoid. It has finger grooves like the cups. And Edard says that the finger holes are placed in a peculiar way. It would make it almost impossible to play."

“Well, perhaps Ame has an answer. Here we are. This is her bailiwick over here."

He steered Mim toward one of the open bays on the perimeter of the floor, under the overhang of the first balcony. The bay was perhaps a quarter acre in extent. The bones didn't take up as much room as the artifacts.

Ame came over to greet them. Her handful of assistants were working at tables with brushes and scrapers and buckets of plaster. One bushy-headed fellow was glued to a computer screen that showed animated images comparing the ways hip joints rotated.

“Bram-tsu-fu, Mim-tsu-mu!” she said, her face radiant with pleasure. “I'm so glad you could come!"

“How are the twins?” Mim asked, giving her a matriarchal kiss.

“Jabbering. And getting into things. Smeth's watching them now. We have rooms at the guest house across the moon plaza. But I think I'm going to ask him to take them back to the tree. The low gravity isn't good for their bones while they're growing.” She laughed. “Besides, they're enough trouble in two dimensions without having them flying through the air as well."

Bram looked across at the row of skeletons wired upright to metal stands. “It looks as if you've put together some fairly complete specimens since I was here last."

“Yes,” Ame said, looking pleased. “We were lucky enough to stumble across a burial ground. They seem to have interred their dead with much ceremony. That was a bonus. We're learning quite a lot about their technology from the grave-objects. Don't be deceived, though. The skeletons aren't quite as complete as they look. We've filled in a few missing parts with plaster and resin by mirror-imaging, inference, trading bones, and so forth."

Bram stopped the eager flow of words with a raised eyebrow. “Burial ground?” he repeated. “What did they die of?"

“Accidents, some of them. Degenerative diseases. Old age."

“Old age!” Mim exclaimed. “But human beings are immortal!"

“Not always, Mim,” Bram reminded her. “The immortality virus was an addition to Original Man's message. It came somewhere between the cycles of the transmission.” He turned expectantly to Ame. “The burial ground must have dated from the earlier epoch of the diskworld, then?"

“No,” Ame said. “That's the problem. We haven't dug down that far yet. Though the levels are mixed in ways they ought not to be—they've been disturbed."

“How recent, then?"

“From everything we can surmise from the skeleton remains, the grave objects, the kitchen middens, and all the rest—the most recent habitation of this city was only about twenty-eight to thirty million years ago."

“Original Man's heyday was more than twice as long ago as that. Could you be mistaken?"

“Radiometric dating confirms that figure pretty much."

“Original Man's civilization fell,” Mim offered. “They lost their immortality. Forgot everything. Struggled up from barbarism. Then a new civilization emerged. Went star traveling again. Found humanity's old beacon and began digging through the ruins—same as we're doing."

“That might fit,” Bram said. “The mixed levels. And some of the artifacts. They're more primitive than the diskworld itself would suggest. That eight-wheeled jointed machine with the armored portholes and those crude metal-spring tires to absorb bounce in low gravity, for instance. Even we're beyond that, with our Nar technology. Doesn't it suggest a race with reborn self-confidence in the first flush of star travel?"

“Come over here,” Ame said. “I want to show you something."

They followed her to the row of skeletons. A young assistant looked up from her work, smiled, and went back to wiring vertebrae together on a half-completed specimen.

“I've never seen a human skeleton, of course,” Ame said. “Just Doc Pol's ultrasonic hologram of one. But you don't have to be an expert to see that these skeletons aren't right."

She switched on the hologram, which appeared in a tinted plastic booth at the end of the row of skeletons, like one more skeleton frozen in a block of ice. Bram glanced at it for comparison, then turned his attention to the others.

The long-footed skeletons were approximately human size and shape and looked remarkably similar to Doc Pol's study model if you discounted the long tail. But even without recourse to the hologram, Bram could spot the anomalies.

“They have the same general body plan as we do,” Ame said, “and the same major bones in the same places. But the arms are too short. The upper and lower leg bones are in the wrong proportion. The thumb opposes, but it's the same length as the fingers. The cranial structures are wrong—the skull has about the same volume as ours, but it's long rather than domed. And the dentition is very different."

“And then there's the tail,” Mim put in.

“Yes,” Ame said. “Evolution might have made many changes in man over a forty-million-year period, but surely it would not have given him back his tail."

Bram chewed his lip. “It is possible, you know. There's such a thing as back mutation or reversion. The mechanism isn't well understood. But in this case you might envision it as the loss of a ‘switch-off’ gene that was an earlier mutation causing taillessness in some hominoid ancestor of man. The loss would leave the redundant tail genes that were still part of the DNA free to express themselves again."

“You mean we could all grow tails again?” Mim said, wide-eyed. “I don't think I'd like that!"

She cast a distinctly worried look at the short-armed, long-footed skeletons with their long whiplashes of added vertebrae.

Bram laughed. “It must have complicated their space-suit design, I'll say that."

“Oh, we've found an almost intact space suit,” Ame said. “The tail sheath was quite ingenious, with a whole series of little bleeder valves that allowed the tail to curl all the way around in a prehensile grip. Even in moderate gravity, they could have hung from their tails, leaving both hands free. We turned the suit over to one of the technology evaluation committees. You can see it on the upper balcony if you like."

“Ame, how large a population of them was there?"

“It's too early to answer that, but it must have been in the tens of thousands."

“Too few to have filled this city, too many to have been just a scientific expedition. Ame, what were they doing here?"

“I can't tell you that, either. We know that one of the things they were doing was exploring these ruins—just as we are. In fact, they've made our work a little easier. We've found at least one of their digs and its repository. They seem to have brought things up from a lower level one where the artifacts definitely were made for hands like ours—and they've arranged and cataloged their finds most conveniently."

“Longfoot archaeologists."

“Yes. They seem to have been just as interested in Original Man as we are. But the level of archaeological activity wasn't high enough to explain their numbers. Otherwise, the whole place would have been dug up."

“And yet they lived and died here."

“For several generations, at least. We've found parts of children's skeletons, too, and fetal bones along with the skeleton of one pregnant female. Bram-tsu, they gave birth to a dozen young at a time."

“That doesn't sound like human beings,” Mim said.

“No, not even after thirty million more years of evolution. But on the other hand, thirty million years before our line diverged from the hominids, our most probable direct ancestor was a small tree-dwelling animal called Aegyptopithecus. It was about the size of a Cuddly and looked something like a cat.” She halted. “Do you know what a cat was?"

“Yes. The little furry animals in the Goya painting."

Ame nodded. “So you see, a lot can happen in thirty million years, even in the human line. Tail aside, the longfoots don't seem that different from us."

Bram said, “Ame, what were they?"

“We're going to do some DNA studies and protein sequencing as soon as we can scrape together enough material. I'll let you know."

He got the answer to one of his questions a couple of Tendays later.

He was sitting in the cubbyhole he used as an office, going over Yggdrasil's accounts—one of the more onerous chores he had to do as year-captain. Enyd had sent him an enormous stack of tally sheets—glucose balance; starch reserves; projected production of fats, oils, alcohol, and glycine over the next kiloday; currently available hydrogen and oxygen—and he was expected to okay the allocations today, if not yesterday.

The rasp of the intercom made him wince.

“I'll get it!” Mim called. He heard her speak to someone, then she poked her head in and said, “That was Smeth from the trunk. The expedition's just docked. Trist is on his way down now."

“What's his hurry? You'd think he'd want a little time to collapse first and get reacquainted with Nen. Or at least allow himself to be lionized for a few hours."

Bram had been back on board Yggdrasil for only a few days himself; he'd left the disk city with the question of longfoot ancestry still unresolved. He'd had to plunge immediately into his accumulated paperwork and other duties, with no time to think about the matter further.

“Nen's in surgery with Doc Pol,” Mim said. “Somebody managed to fall down a tracheid and smash an ankle. Trist prepared a preliminary report on the trip back. But he said he thought you'd want to know right away."

“Know what?"

“That,” she said, “is what he's on his way down to tell you."

Trist arrived twenty minutes later; he must have been in free fall all the way. His yellow hair was disheveled, and he had a ripe space suit aroma—Lydis was still making her passengers suit up for drops and dockings—but he was full of unleashed energy, and his blue eyes, though rimmed with fatigue, sparkled.

He refused Mim's offer of tea—a new custom instituted by Marg after she had read about it in some of the library material that had been brought up from the diskworld, subsequently experimenting with infusions brewed from Yggdrasil's bark—and got right to the point.

“We did a thorough survey from space, of course,” he said. “Went as close to the hub as Lydis dared. Spotted over a hundred of the sites over a nine-hundred-billion-square-mile area. Some of the structures were still inflated after all this time; others were flat as corncakes. It was pretty obvious what they'd been up to. But we couldn't be absolutely certain till we made a landing and deployed the climbers. We managed to visit four locations—brought back some goodies for the archaeologists, too."

“And,” Bram said, knowing the answer, “what were they?"

“Camps,” Trist said promptly. “Work camps. They must have lived there deciyears at a time, repairing antenna elements, installing their own equipment to fill in the breaks."

“They were trying to make the system operational again?"

“That's the only conclusion that can be drawn."

Bram leaned back and stared into space for a moment. “That would have been a tremendous undertaking, even with a work force of tens of thousands—or many times more than that, it may turn out. It would have meant committing themselves for generations."

“They were willing to do that, apparently. Bram, can you imagine the conditions they must have endured in those inflatable camps? The ones closer to the horizontal gravity sectors were built out on scaffolding—with no place even to stand for kilodays, except for the tents and stringers. Dangling over eternity all that time while they worked. It wasn't much better closer to the hub. Trying to adjust to the crazy angles, under heavy gravity with your weight tearing sideways at you. With the danger of falling with every step and an awareness of the penalties if you did. We didn't set foot within ten million miles of some of the farther camps, and I can tell you, I still didn't like it!"

Trist hadn't heard about the tails. Bram told him.

“Whew!” Trist whistled. “That explains it. You'd need a tail to work in a place like that."

“Ame thinks they may have been a species other than man. But the verdict isn't in yet."

“A new species to supersede man. I'm not sure I like that idea. It was one thing to deal with the idea that human beings were extinct. We've more or less accepted that from the beginning. But the idea of another species taking our place—that's something else again. Gives us competition in this neck of the galaxy, Bram. The planet Earth may be overrun by these long-footed characters. Where do we go, then?"

“They may be our cousins."

“Makes no difference. The fact that they were getting ready to patch up Original Man's beacon tells us all we need to know. Different species or different order entirely, they were preparing to spread their own image through the universe. It bears out that old idea we used to talk about long ago, before the Nar sped us on our way to this galaxy—that there comes a time in the life of every intelligent species when it begins to dawn on them that the means is at hand for species immortality."

“Yes, I remember."

“Now we've got three cases. Original Man, broadcasting his genetic code to the Virgo cluster and beyond. The Nar, sending us to the heart of their own galaxy to do the same job for them. And now these people with tails. Except that they're a little premature. They were able to take advantage of an installation that somebody else built. Bram, I just had another thought!"

“What is it?"

'You said that these tailed people weren't immortal. Neither were the Nar. Neither was Original Man when he started broadcasting. What if this compulsion to spread around your genetic code is a stage that a species goes through before it attains personal immortality?"

“Hmmm. The night doesn't seem so dark, then. The universe isn't a bottomless hole. There's time. Time to travel to the ends of the universe yourself someday. At least that's what the little nagging voice inside you would be saying. Trist, you don't suppose..."

“That Original Man never became extinct? That he simply gave up, packed up and went home after he'd been infected with eternal life long enough for the idea to sink in?"

“Yes. And then, somewhere along the way, acquired an immunity to immortality. Forgot things. Evolved into a new species. And then one day set out on a path to the stars again. And found the old beacon."

“As I said before, it hardly matters. Whoever they were, they're not us."

“I'd like to send an expedition to one of the inner disks. And to the next disk ahead of us in orbit—see how close a duplicate it is to this one. We may have landed in the wrong place."

“I'd give my spare shirt to go. But Bram, there isn't time—"

“I'm going to call a tree meeting and call for a vote to stay here an extra year. We're digging up treasure troves of material—whole libraries of it, and we've only scratched the surface. I want to get as much material transferred to Yggdrasil as we can. We can't abandon a working party here, no matter how many eager volunteers there'd be. Not when the only habitable body in the known universe also happens to be our only starship. And there's no telling when we'll be back this way. It may be centuries before we grow another Yggdrasil and outfit it and can spare a population to crew it."

“A year.” Trist furrowed his brow. “I'll have to work out some orbits. The distances are huge, of course, but it's not like ordinary interplanetary travel here ... hmmm, we've got a body whose own orbital period is a year as our catapult, with no gravity to speak of to fight ... add a modest boost...deboost to end up a hundred twenty degrees ahead ... and for the return trip, a retro-orbit to lose orbital energy and rendezvous with your starting point in somewhat less than a year.” He gave Bram an engaging smile. “But I get Nen to go along with me as a medical officer."

“Done,” Bram said.

Mim appeared with a tray. “Don't worry, it isn't tea,” she said. “Just old-fashioned cornbrew and some snacks."

“Mim watch out!” Bram shouted.

A little ball of fluff streaked between her ankles and almost tripped her. She recovered her balance and managed to keep the tray level without spilling anything.

“Loki!” she scolded.

The Cuddly scampered up Trist's leg, paused at his knee to be patted, then climbed to his shoulder and pulled at his yellow hair.

“Loki, get down and behave yourself,” Bram said. He apologized to Trist. “He gets into everything."

“Oh, that's all right, we have one of our own,” Trist said. He scratched the little creatures's neck. “Where'd you get the name?"

“Loki? It was an old human god who was always getting into mischief. It seemed to fit."

“Nen named ours Fluff. If she doesn't stop overfeeding it, we'll have to rename it Sphere."

“It's hard to resist one,” Mim said. “They're the best thing we're taking with us from the diskworld."

Loki sat up and chittered at her as if he knew what she was saying. Trist broke off a corner of one of his cornsnacks and gave it to the little beast, which held the morsel in both paws and began nibbling at it.

“Yes,” Bram said. “I think they mean more to us than we realize. They're the first terrestrial life form that humans have ever seen, after all."

“Other than vegetables,” Trist said, popping a potato crisp into his mouth.

“Vegetables that we engineered ourselves or the Nar engineered for us. But Trist, just think of it, these little creatures carry an unbroken line of DNA that goes all the way back to the world that gave us birth."

“DNA calls out to DNA, is that it?"

“Something like that. We know without having to think about it that these little animals are a precious link with an earthly heritage."

Idly, Trist scratched the Cuddly behind one ear. It made a contented sound and snuggled against him. “There's something wrong there,” he said lazily. “The first human being, as far as we're concerned, was mixed up in a test tube by a Nar bioengineer. From native materials."

“Ravel is Ravel,” Mim said. “No matter what instruments play it."

“Hah! Good for you, Mim!” Trist conceded. “I'll desist.” He took a sip of his drink. Loki tried to poke his muzzle into the cup, and Trist let him have a taste. The Cuddly sputtered and spat it out. Everybody laughed.

“Abstemious,” Bram said. “Maybe we can learn something from them."

Trist fed the little pet another fragment of cornsnack to appease it. “It would be nice,” he said, “to go home to an Earth that was inhabited by Cuddlies instead of those tailed people with the long skinny feet."

“Not likely,” Bram said. “Ame says the Cuddlies evolved on the diskworld from more primitive forms. That isn't to say that some collateral branch with similar traits couldn't have evolved on Earth in the meantime.” He frowned. “But we know what life form achieved dominance on Earth, don't we?"

“They were rats,” Ame said.

She stepped back to let Bram have a better look at the exhibit that she and her section had prepared. Two of her colleagues—Jorv, the bouncy baby-faced zoologist whom Bram had met before, and a tall bony young woman named Shira, who was something called a “paleobiologist"—stood by with eager expressions on their faces.

Bram raised an eyebrow. “Rats? The pests of the ‘Dappled Piper’ legend?"

He scuffed cautiously closer. He hadn't had time to readjust to diskworld gravity yet, and he was still stiff and tired from the ferry trip to the surface, though it was down to five days now.

“Rattus norvegicus to be exact,” Ame said. “The most successful member of the family and the one that would have been in the best position to succeed Original Man after man's activities had changed the environment. They were highly adaptable, they were omnivores as humankind's ancestors were, and in fact they resembled some of the primitive specimens on our own family tree."

The computer-generated hologram showed three skeletons in the same scale. The center one was a life-size projection of Ame's most complete longfoot skeleton—the one Bram had noticed when he first entered the work-bay. He recognized the skeleton on the right, too. It was Doc Pol's familiar ultrasound figurine, the textbook example that Doc had learned his own trade from and that he now required his apprentices to memorize.

The third skeleton was something else entirely. Though the computer had made the bones stand in an upright position, the proportions were grotesque. The torso was absurdly long, with tiny little hands and feet and a head that was much too large for it. The bones would have been too spindly to support the creature in normal gravity. Bram saw immediately that the creature must have been a very small animal that the computer had brought up to the size of the other two skeletons for purposes of comparison.

Ame touched a button, and lines flashed from the center skeleton to the other two, showing correspondences. Though the longfoot skeleton and the human skeleton were superficially similar, it was immediately apparent that the disproportioned skeleton on the left had more in common with the longfoot specimen.

“You can see that what appears to be a backward-bending knee is actually what became a heel,” Ame said. “The creature would have walked on its toes. The shaft of the leg bone became a long, narrow foot. And of course, the tail is there, bone for bone."

“Ame, this is marvelous,” Bram said. “I'm enormously impressed. How did you do all this?"

She looked pleased. “We had a breakthrough. Literally. One of the digging machines broke through to a layer where the stratigraphy had been disturbed. The longfoots had been busy there. They had a—a sort of museum of their own there. And a library. And biosample vaults. They had brought up and catalogued a whole biological cornucopia preserved by Original Man. It must have come as a wonderful revelation to the longfoots. They were interested in their own ancestry, you see. Original Man's records predated their own fossil records."

Jorv's plump face beamed complacency. “Original Man did all the work for them,” he said, “and they did all the work for us."

“We don't have enough archaeologists to go around,” Ame said, “but all the amateurs are well trained by now. As soon as the digging machine operator saw what he was bringing up, he stopped, roped off the place, and notified the proper people."

“As soon as they saw they were bringing up biological specimens, they got us," Jorv bubbled. “You wouldn't believe it! There were mounted skeletons. Arranged in classifications. And metal plaques to explain them. And supplementary materials—actual books preserved in nitrogen. And tapes and holochips. In Inglex and Chin-pin-yin. The longfoots probably couldn't read them, but we could—right away!"

The attenuated paleobiologist, Shira, ran nervous fingers through stringy brown hair. “And there were actual tissue samples, too, still in a remarkable state of preservation. The rat-people—longfoots—had broken some of the seals, but others were intact. We were able to extract enough DNA and protein for sequential analysis."

“There'll be more,” Jorv interrupted. “We've only scratched the surface with this find. We're trenching now, looking for the rest of it. And they thought zoology was a theoretical science! Bram-companion, when we get to our world, we'll be able to recreate species! Stock our streams with trout, our forests with trees other than poplar! Did you know that Original Man had his own bio-vehicles—a sort of walker called a horse!"

“Well, that's certainly a program for the future,” Bram said noncommittally.

Shira continued serenely, as if used to interruptions. “Until now, we've lacked the capacity to do molecular taxonomy in any meaningful way. Oh, we've been able to use cytochrome c sequencing to demonstrate that human beings are very far removed indeed from yeast—forty-five amino acid differences—not quite as far removed from cabbages, and closer still to heterochronic eggs. But now, of course, we have all those lovely tissue samples."

“Horses,” Jorv said dreamily. “Zebras. Giraffes. Rhesus monkeys. Wolves. Original Man preserved them all."

“And of course we've brought up scads of mouse bones from our deeper excavations. Man inadvertently carried mice and other vermin to the diskworld with him—just as, I suppose, he carried them with him everywhere he went. The mice didn't manage to survive for long after humans departed the diskworld. They never adapted for airlessness, they weren't able to burrow deep enough, and they quickly exhausted the more easily available sources of food. We found no mouse bones more recent than seventy million years old. But they still contained traces of cytochrome c."

“And we had ourselves and Cuddlies available as a source of hemoglobin and serum albumin,” Jorv said. “Oh, there was no doubt at all!"

Shira brushed her hair back. “The longfoots were at several removes from us and Cuddlies—well beyond the limits of family or genus, let alone species. Farther still from Jorv's giraffes, though we were able to do only DNA sequencing in that case. But the molecular differences between longfoots and mice—"

“Mus musculus," Jorv interjected. “Same family as rats. If you remember your childhood Chin-pin-yin, it's the same word. Big-mouse."

Shira spared a tolerant glance for Jorv and finished what she had been saying. “...but the molecular differences between longfoots and mice were practically nil."

Bram nodded at the longfoot skeleton. “That seems to settle it, then. Man did become extinct. And the next dominant species was that."

Ame said, “We found something else."

“What's that?"

“We know how the Cuddlies got here."

Bram picked his way down the tunnel, following Jorv's bobbing yellow light. Loose gravel under his feet started slow-motion cascades as he proceeded, coming to rest long after he had passed. The lanky paleobiologist was right behind him, shedding enough light of her own for him to see by, and Ame brought up the rear. Bram, as an escorted guest, went unburdened; the other three wore many-pocketed tabards over their space suits and lugged an assortment of picks, hammers, and other small tools.

After what seemed like an endless trek, the tunnel opened out into a wide, low-ceiling space shored up by timbers. Other tunnels branched off the space, glimmers of light from a couple of them showing the presence of other work parties.

The thick timbers were ordinary vacuum-poplar. Seeing them brought a lump of homesickness to Bram's throat till he remembered that vacuum-poplar had originated here, in the Milky Way, not in the Whirlpool galaxy.

Ame saw him looking. “The longfoots dug up a human lumberyard near here and took advantage of it. The wood must have been in vacuum and still good. Before that—” She indicated the branching tunnels where archaeological work was in progress. “—the longfoots used columns of native stone as well as steel griders that they brought with them. Evidently they didn't have much of a structural plastics industry. It bears out your theory that they were a young civilization, newly come to star travel, Bram-tsu."

“What was this place?"

“The longfoots had some of their own storehouses here. And living areas close by. We gleaned some insight into their social habits. There was some limited pair bonding in our sense, but mostly they lived in aggregates of fifty to a hundred members in which females were available to males on some kind of schedule of dominance. The living arrangements pointed to that, anyway. The females raised their young separately and cooperated in keeping males at bay for a period after parturition."

“They don't sound like a very pleasant people."

“Rats don't make very pleasant ancestors."

Bram shuddered, remembering the fragment of film Ame had been able to show him. It had been part of an exhibit associated with the mounted rat skeleton and had shown a bedraggled brown animal with beady eyes and a naked tail greedily eating its way thorugh a store of corn, excreting as it went. Bram had been ashamed of his instant and automatic revulsion, telling himself that the rat was a life form like any other, with a right to existence. But Ame had told him that his reaction wasn't unique—that rats seemed to raise the hackles of most humans.

“You're being narrow-minded, Ame,” Jorv protested. “Seeing it from a human point of view. Different species, different biological imperatives. They might have been a perfectly decent folk. They acted cooperatively, after all."

“Come here, I want to show you something,” Ame said.

She led Bram to a cache where specimens had been arranged with preliminary labels. There were bins of a dessicated, unfamiliar grain, shovel-size scoops, a broken ceramic jug.

But what caught Bram's attention was a small animal skeleton on a slab of wood. The skull was crushed, pinned to the slab by a copper bar that was attached to a large spring. But enough could be seen of the jaw to show that it was still clenched around something that looked like a fossil nut, which was attached by a wire to a sort of pivoting tray.

“A trap,” Ame said. “The animal in it was a Cuddly."

Shira tossed her lank hair back within the bowl of her helmet. “They poisoned them, too,” she said. “We've found piles of Cuddly bones around a feast of that same bait that one of them would have brought back to the burrow for the females and young ones."

Bram was appalled. “But what a terrible thing to do."

“No more terrible than what Original Man did to rats,” Jorv said.

“The longfoots carried their own vermin into space with them, just as man once carried rats and mice,” Ame said. “That's what the vermin were. Cuddlies."

“The Cuddlies’ ancestral form, actually,” Shira said. “They hadn't evolved for airlessness yet. You can see that the rib cage isn't enlarged for accessory lungs. And the toe of the rear foot is not fully opposable."

“But I think that if we were to see one of these creatures in its fur,” Ame said, “we'd see it as a Cuddly."

Bram studied the trap with distaste. “Ingenious and cruel,” he said. “The victim had to tug at the bait to pull it loose, and that released this strut that kept the spring armed. The animal's head would be in position for the copper bar. Even if its reflexes were good and it drew back, it would still get its neck broken."

“These little animals were pests," Jorv said. “They got into the longfoots’ food supply. They were probably unsanitary. And they probably bit."

“The longfoots tried diligently to exterminate them back on Earth. We found a sort of children's picture book with a story about it. But the creatures must have been too clever, or too prolific, to be stamped out entirely. The longfoots must have been horrified to find that they'd transported them here."

“Well, the Cuddlies outlasted the longfoots here, at any rate,” Bram said grimly. “Long after these ... rat-people packed up and went back to Earth, The Cuddlies were able to survive on the diskworld long enough to adapt for vacuum. To adapt for space travel, when you stop to think about it—when you see the way they scamper around Yggdrasil's branches and seem to enjoy it."

“Their root stock must have adapted back on Earth, too,” said Shira.

“Yes,” Ame said “If the human race was never able to exterminate rats, and the rats developed into an intelligent species after man was gone, the same might be true for the proto-Cuddlies. They might be the longfoots’ successors back on earth by now. After all, they occupied a similar ecological niche."

“What a delicious thought, Ame!” Shira exclaimed. “A world ruled by cousins of the Cuddlies! But would a six-foot intelligent Cuddly be as huggable?"

Ame laughed. “I can hardly wait to get to Sol and see. But Bram-tsu, we mustn't leave till we finish our work here."

“That won't be for a while,” Bram said. “We had an all-tree meeting before I left. You've been voted an extra year."

The long plain was dotted with depots of crated material, each with a little band of partisans gathered around it vying for priority. Processions of cargo walkers, roped together in long caravans led by space-suited drovers, plodded across the starlit diskscape toward the staging areas where the rocket-assisted pallets were being loaded. All the wheeled vehicles had been pressed into service, too, and they could be seen bumping lazily across the flat vista, some of them achieving temporary flight.

Bram, helping Jun Davd to cinch a saddlebag full of astronomical data in place on a kneeling walker, paused in his work to watch a shower of sparks lift above the horizon and rise toward the blob of silver light that was Yggdrasil, hovering just to the right of the pendant moon.

“That's the third in an hour from the other side,” he said. “The museum's launchpad, it looks like. They must be working overtime."

“They're overloading their pallets,” Jun Davd said. “I'm surprised some of ’em got off the ground. I was over there yesterday helping the dispatcher to figure weights and balances, and we had to make them take off a big statue of three naked men wrestling a snake. Would have spoiled the trim—had the platform tumbling end over end. Had one of those art fellows almost in tears."

“I'm sure they got it off later."

“They've had a year and a half to loot that museum. I thought the idea was to take a small representative sample and leave the rest for the ages—or for whenever we can get back this way."

“You know how it is. All of a sudden we're about to leave, and they start having second thoughts. There's this last-minute rush. Everybody's suddenly discovered that there are things they just can't bear to leave behind—the historians, the archaeologists, the agronomists, everybody.” He laid a hand on the saddlebags. “You, too, it looks like."

Jun Davd grunted. “It just occurred to me that it might be a good idea to abscond with part of the backlog of original plates—do you know, their astronomers were still recording images on light-sensitive paper for centuries after they had more advanced methods available? Oh, I've got all the electronically stored data I need, but it'll take years—decades—to go through it all, and I started worrying about accumulated signal errors."

“Have you made any more progress in locating Sol?"

“There are four candidates in the immediate stellar neighborhood. I've all but ruled out three of them—but I want to refine my mass estimates a bit further before I set a course out of this system."

“Waiting until the last minute, are you?"

Jun Davd hooked a thumb over his shoulder in the direction of the red-rimmed world-edge that overlooked the masked sun.

“I think I've identified our hidden friend, though. It must have been the star they called Delta Pavonis."

Bram tried not to show his disappointment. “Well, it's a possible reference point, I suppose. Though the relative positions of the stars in the neighborhood will have changed a lot in seventy-four million years."

“Delta Pavonis was almost Sol's twin,” Jun Davd went on serenely. “It was a G-type star with ninety-eight percent of Sol's mass. It was about nineteen light-years distant. The other nearby G stars had masses of eighty or ninety percent of Sol, except for one called Beta Hydri—that was about one and a quarter solar masses—and one other exception. So the invisible star we're circling almost has to be either Sol or Delta Pavonis—and I think we've already agreed that Original Man would hardly have dismantled his own system for a radio station."

“Or it could be an interloper. A wanderer they used."

“In that case, the proper motion of all the nearby stars would be much greater than we've observed during our stay."

“Oh, right.” Bram blushed like an apprentice. After more than five centuries of subjective time, Jun Davd could still make him feel like the little boy whom Voth had sent to the observatory to take astronomy lessons.

“The interesting thing is that the other exception is also almost a twin of Sol—a G-4 of one point oh eight solar masses."

“So we still can't tell which—"

“Except for the fact that it was part of a triple star system that went by the name of Alpha Centauri. Which also happened to be Sol's closest neighbor—just a shade over four light-years away."

With mounting excitement, Bram began, “That means—"

Jun Davd nodded. “On the assumption that stars that close might have been gravitationally bound—however tenuously—I searched for matching G stars about that distance apart, one of which was part of a triple system.” A grin spread slowly across his dark face. “They're still there, drifting hand in hand through the spiral arms, and they haven't changed position much with respect to Delta Pavonis, either."

“Jun Davd, you're incorrigible! I'll never forgive you for keeping me in suspense like that. How far?"

“Less than twenty light-years. Boosting at one gravity, we can be home in seven subjective years."

Home. The word had a strange ring to it. Bram slapped Jun Davd on the back. “Let's hurry and get started, then."

The walker, misinterpreting the slap, rose to its full height. The drover came over and said, “Are you ready to go?"

“In a minute,” Jun Davd told him. He turned back to Bram. “There's one more datum."

“What's that?"

“The G star that seems to be Sol happens to be at the exact center of the sphere of radio clicks that's growing our way. As if it were the focal point."

“Original Man!” Bram whispered. “He has come back!"

Jum Davd shook his, head. “That doesn't seem likely. We've had the longfoots in between. We may be about to meet the next contender on the evolutionary treadmill. Or Smeth may be right. It may be a natural phenomenon. In any case, we'd better go. see."

He picked up the remaining pair of saddlebags and slung them over his own shoulder. The other walkers in the caravan, feeling the tug of the rope, struggled to their feet. In a few minutes, Bram and Jun Davd were following the swaying line of biotransports down the well-scuffed trail to the staging area.

There were plenty of willing hands at the other end to help the caravan unload. Ame was there, supervising the lashing of some bulky crates to an enormous wooden frame whose booster rockets, bolted to the corners and along the sides, must have added up to a hundred thousand pounds of thrust. Bram also spotted his son, Edard, clambering around at the top of a mountain of freight, unfurling a cargo net. Edard saw him and took a nicely calculated leap that brought him floating down to within a foot of where Bram and Jun Davd were standing.

“Hello, Father. Hello, Jun Davd. What have you got there? Documents mostly? If you have anything fragile, I've got room for it with my stuff. I'm riding with the supercargo this load, and I can keep an eye on it for you at the other end."

Edard was fair and slender, with a suggestion of epicanthic folds at the corners of his eyes that must have come from mama-mu Dlors after skipping a generation. Bram was sorry that Edard had never met his partial gene grandmother; Dlors had elected to remain on the Father World. As a dancer, she had been part of the musical world, and she would have been as proud of Edard as if she had been any latter-day grandmother contributing a full complement of grandmotherly genes.

“You're going to ride that thing?” Bram asked, casting a dubious eye at the rickety pile. “In nothing but a space suit?"

“It's only a few hours to Yggie now, and the super's got an extra bottle of air he's willing to share,” Edard said cheerfully.

Ame sauntered over. “Everybody's hitching rides now,” she said. “I'm going to ride up with my last load, too. I'm saving the delicate stuff for then."

Edard cast a glance upward to where the silver shape of the space tree hung overhead. “Got to take advantage of Yggie's favorable position while it lasts. Look at these mountains of souvenirs around us. It'll be half a Tenday before we load it all, and then we've got to get the walkers and heavy equipment up there, not to mention packing up our own personal odds and ends."

Bram conceded the point with a nod. Before coming down to the surface on this final trip, he had given the order for Yggdrasil's rotation to be stopped. The tree's inhabitants could put up with weightlessness for the few days it took to make the final transfer of goods. The swarms of cargo pallets were landing all over the branches. The limited docking facilities at the hub were being reserved for passenger vehicles.

“I'll accept your offer with thanks,” Jun Davd said to Edard. “Here, give me a hand with these boxes of instruments. Be careful—there's a lot of glass."

Edard pitched in, and he and Jun Davd made a number of soaring trips in tandem to the top of the heap with boxes slung between them, while Bram unloaded the walker. Fifteen minutes later it was done. The cargo net was tied down securely over the mound of bales and crates, and the supercargo, after inspecting all the fastenings, walked all the way around the wooden platform, checking the weight distribution at intervals with a jack arrangement that lifted the whole thing off the ground.

While they waited, Bram said to Edard, “What have you got there?"

Edard's face lit up. “Musical instruments. Hundreds of them, all gathered into one place by the longfoot archaeologists. We would never have been able to collect them all ourselves in twenty years of digging! This is my fourth load. Bramfather, the violin—and the other stringed instruments—are entirely different from the way we've conceived them! They had only four strings, and they were played with an ordinary manual bow, not motorized disks or powered friction wands. And the instruments themselves are beautiful, curved, complex shapes sculpted of wood. We'll have to learn how to copy them! We'll hear music we never heard before! But learning to play such devices well will take a lot of practice!"

“Your mother will be pleased.” Bram could not help thinking of Olan Byr, who had devoted his life to reinventing the old instruments.

“I've already given her one of the cellos,” Edard said. “On my last trip a few days ago. She was practicing on it when I left."

“We're filling in all the blank places in human culture,” Ame said. “Books of art reproductions—shelves of them. And thousands of actual paintings and pieces of sculpture from the later centuries. And holos of opera, dance, and dramatic performances. And in my field, a complete survey of terrestrial paleontology going back four and a half billion years."

“Biology, too,” Bram said. “We have a complete DNA library of thousands and thousands of plant and animal species.” Those had been among the first treasures to be moved; they now were in storage aboard Yggdrasil.

Edard hardly listened; he was carried away by his own enthusiasms. “And musical scores! More than nine hundred compositions by someone named Schubert—songs, symphonies, quartets! He must have lived after the discovery of immortality to have written so much! And thirty-two piano sonatas by Beethoven, all of them strikingly different. I never knew he'd written so many! And operas by Mozart! Oratorios by Handel! They all belong to us again!"

“We'll look forward to your next concerts,” Jun Davd murmured.

The super made a few last notations on a tablet with a vacuum stylus, scribbled his initials, and tacked the sheet to the pallet frame. “All set,” he said.

Edard climbed to a perch atop his possessions, got a firm grip on the cargo net, and waved. A Cuddly rode his shoulder. Bram, Ame, and Jun Davd stood well back with the caravan master and line of walkers. Flame bloomed behind the splash skirt, and the heavily laden platform lifted ponderously, seemed to hang poised for several seconds, then rose with increasing speed into the black sky.

Around Bram the tethered walkers pawed the ground in response to the vibrations. Their attendants calmed them by stroking the affected pseudoganglions. Bram followed the yellow square of flame with his eyes as it climbed toward the hovering tree.

Bram's eyes were still turned upward when Jun Davd grabbed his sleeve and said, “Look!"

Somewhere past Yggdrasil a new star bloomed. It was a bright blue spark, moving rapidly across the field of stars. It lost its proper motion and turned brighter.

“I believe it's a fusion flame,” Jun Davd said calmly.

The caravan master and drovers, following their gaze, gaped skyward. On the surrounding plain, activity slowed and stopped as other people noticed.

The blue spark was the brightest star in the sky. It moved not at all against the constellations now.

“They made their course correction,” Jun Davd said. “It appears that this is the disk they've chosen."

“Where...” began a stunned Ame.

Jun Davd squinted at the strange new constellations that had taken shape after seventy-four million years. By now he knew them by heart. “They seem to have come from the general direction of Sol,” he said. “Of course, it was inevitable that they'd get around to Delta Pavonis sooner or later."

“All those clicking stars...” Bram said.

Jun Davd nodded. “They had to be some manifestation of their message traffic, whether we could extract a pattern out of it or not. And they spread like a tide—not by exercising choice. Inhospitable places like red giants and the burnt-out cinders of white dwarfs, whose planets have no future. You'd think they would have skipped to a few of the more congenial stars first. And now their wave front's arriving here, like clockwork."

Bram drew a sharp breath. “But why now?” he said. “Why not sooner? Or later? No one's visited the disk-worlds for over fifty million years. And just as we get here..."

Ame's face was flushed behind the sparkling curve of her helmet. “Because it's their turn, don't you see, Bram-tsu!"

“Your extinction timetable?"

She nodded vigorously. “The figures work out about right, don't they, Jun Davd?"

Jun Davd spoke without removing his eyes from the distant fusion flame. “We came back here in a multiple of thirty-seven million years—just as fast as we could after the Message reached the Father World, not counting the few insignificant millennia that fell through the cracks while the Nar remade us, and so forth. They got here in a rough multiple of twenty-six million years after the Message stopped.” He pursed his lips. “They seem to have arrived about four million years early. That's within the limits of your timetable, isn't it, Ame?"

“Divided by three, yes,” she said.

Around them on the booty-littered plain, people were gathering into groups, pointing excitedly at the sky. Bram knew that if he switched to the general frequency he would hear a babble of voices. A delegation of about a dozen people, spotting Jun Davd's tall space-suited figure and his own well-worn tabard, were bouncing across the fiat ribbonscape toward them.

“Who?” Bram said. “Relatives of the Cuddlies? The collateral branch you postulated that might have evolved from the same root stock after the longfoots carried the Cuddlies here?"

“No,” Ame said. “That would have been the last cycle—twenty-six million years ago. The proto-Cuddlies missed their chance. They never traveled to the stars."

Bram stared at the blue spark that was heading toward them. “Who then?” he said.

“We'll know very soon,” Jun Davd said.