After all the while since last they trod the decks of Envoy, to do so felt less like a homecoming to Mokoena and Zeyd than like entering a house — a labyrinth — long forsaken and half forgotten. Cabins lay empty. A whisper of ventilation only deepened the silence in the passageways.

Yu proceeded more matter-of-factly. Her involvement in designing an acceleration compensator had already brought her aboard several times. The biologist they called Peter trailed along, impassive in ens foreignness.

A larger number of Tahirians than had gone to the pulsar would fare to the black hole. Expanding quarters and facilities for them meant more than simply clearing out another storage compartment or two. Zeyd had quipped that the spaces under consideration bore no obvious relation to the stars.

"As for the occasional magnetic stimulation they need for comfort and long-term health," Mokoena said, "I suggest that this time, instead of a special cabinet, we provide a field in their new gymnasium."

Yu frowned. "That great a volume?"

"Oh, in a corner, as part of the exercise and recreation equipment."

"It will still take massive superconducting coils."

"Which must not pass too near their food synthesizers, wherever we locate those," Zeyd pointed out. "Induction effects would interfere with the nanos."

"My, my," Mokoena laughed, "this is a jigsaw puzzle, isn't it?"

Peter trilled. They turned to en and reached for the parleurs slung at their belts. "Duibuqi," Yu apologized. "I'm sorry. We left you too much out." Before she could put it in Cambiante, Peter's screen was flickering while ens voice growled.

"(On an expedition as lengthy as this one may become, conditions that were tolerable for a limited time are so no longer. The reduced weight compensates to some extent for the differences in atmospheric pressure and composition, and the previous travelers grew accustomed (resigned?) to the foul odors. They also adjusted to the circadian cycle. However, over a period of more than a year, the lack of weather will prove unendurable.)"

The humans recalled wild shiftings from month to month or day to day, and the geologically swift climatic changes under which this race had evolved. "(Are the variations in our ship too bland?)" Yu asked. "(We shall certainly do something about that. What do you propose? Virtual-reality programs? Your people must have had an answer in their own starfaring era.)"

Peter's mane erected stiffly. They caught an acrid whiff. "(Everything would be unnecessary if you would go away. Go home. Never seek our world again.)"

Yu winced. "(You know that won't happen until we have been to the black hole. Besides, no few among you want to accompany us.)"

"(Unnatural desire. When they return, their kin will be centuries dead.)"

"That may be worse for them than for us," Mokoena murmured.

"No, they'll have the same society waiting for them," Zeyd said as quietly. "We won't."

"Let star travel start up again, and soon that won't be true for them, either."

"(We gave our promise to those who wish to go,)" Yu reminded Peter.

"(And therefore some who are sane must go with them.)" Unspoken: Abandoning our beloved forever. Because of you. "(Ill fortune. I almost hope the expedition will be ill-fated. Then the race can abide in its peace.)"

Yu stood her ground, trying to phrase friendliness. Zeyd and Mokoena moved closer together.

But why me?" Cleland asked, dumbfounded. "I'm no engineer or machine operator or — or anybody who'd be useful in this."

"You're handy enough with your own professional gear," Brent replied, "and what counts for more, you're experienced in free space, including work on the outside of the ship. What you don't know, I'll teach you."

Sunlight and a breath of forest streamed through an open window into his cabin. Cleland looked around, as if the equipment-crowded machine shop in Envoy were somehow hidden behind these walls. "Uh, well, I'll try my best," he said, "but, really, the compensator is Hanny's and Wenji's design, and they ought to oversee the project" — it's construction and installation.

Brent grimaced. "They will, from time to time. However, they're busy elsewhere. Mainly, they'll just keep track of us."

"And as for an assistant, Al, if you need a human to help you, besides the robots, well, Lajos is far better at that sort of thing than I am."

"He'll be busy, too," Brent snapped. "They'll all be working with the Tahirians to make the orbiting observatory station."

"I happen to know Lajos won't be called on very much for that." Cleland flushed. "Al, you aren't co-opting me for this job to give me something to do — because you feel sorry for me — are you?"

Brent smiled rather grimly. "No. The fact is, you can handle your share of it, given some training and supervision, and I don't care to work alongside Lajos Ruszek. Or Hanny Dayan."

Cleland gaped. "What?"

"Never mind! My business. We won't say any more about it, okay?" Seeing the younger man's discomfiture, Brent yielded enough to add: "Look, everybody needs to keep a civil tongue in his head, or the crew'll tear itself apart. I don't want to overstress my self-control. You and I, we get along fine."

"Well, yes — but —"

Brent changed to his persuasive mode, though it was steely, like a commander talking to his troops on the eve of battle: "And we have the same purpose. I know how you want to go home, Tim, an end to this voyage of the damned. Me, I want it so bad it's like a slow fire in my bones. All right, we are committed to the stinking black hole, and we'd better make ready to survive it. But you and I, we can think beyond. We can keep alert for any chance that comes to improve the situation, and keep the guts to grab that chance."

"I'm . . . not sure what you mean. Yes, I'd rather head straight back from here. Still, the science, the discoveries  —  I'll make the best of it I can. Won't you?"

"Of course. The expedition's crazy. But I do have to admit the technology we're developing for it here has potential I can barely guess at  —  for Earth, for our race. And maybe we'll even learn something more where we're bound, not abstract knowledge but something with real-life possibilities. This is the kind of information we have got to make riveted certain we bring home, in a form human experts can deal with. The right experts."

"You don't suppose they already know, back there?"

"I wonder if they do. We've already doubted they'd duplicate every Tahirian idea and invention. What's being created now, a joint human-Tahirian thing — it's instrumentation and control intended for absolutely freak conditions. People in Sol's neighborhood may well never have met any such. There may not be a black hole in whatever radius they've reached, or if there is, it may be different somehow. In that case, they've had no reason to develop systems like these."

"Then what good will it do them?"

"Things have a way of finding uses. Fireworks became guns and the first spacecraft. Nuclear physics showed how to make nuclear weapons and power plants. I can see applications of this stuff — especially if it's linked with robotics from the star cluster and the Tahirian engineering. . . . Power." Brent stared before him. "Power."

The planet hung beautiful at quarter phase, a purple-blue scimitar flecked with rust that was land and banded with silver that was cloud, laid along the dark velvet cushion of nightside. Closer by, though toylike at her distance, the wheels of Envoy flung sunlight back in flashes as they spun about their axle the hull.

Kilbirnie sat harnessed, weightless, at the pilot board of the boat Herald. The Tahirian Colin crouched in the seat beside her, clinging with spurs. Aft of them Dayan and the physicist she knew as Esther floated free at a recently rigged console.

Dayan flicked a switch. From a launching rack outside, also lately built, sprang a slim torpedo shape. It shot off under field drive, diminished into remoteness, became one of several sparks that flitted far-scattered athwart the stars.

After a while Esther nudged her. Red hair waved as she looked about. "(I, too, should practice with this model,)" said her colleague.

Dayan took her own parleur. "(My regrets. I forgot. You are no more familiar with these devices than I am.)"

"(Centuries have passed since my ancestors dispatched any.)"

And into strange conditions, Dayan refrained from answering, since it was needless. Special vehicles carrying uniquely special instruments. Granted, they will be directed by computers, from the inner station we'll orbit. But we have to have knowledge of them ourselves, how they behave, what their capabilities and limitations are, as soldiers need knowledge of even their robotic weapons. Space around the black hole will be our implacable, unforeseeably treacherous enemy.

She concentrated on monitor screens and data readings. Her peripheral vision traced what the flexible Tahirian fingers did.

Kilbirnie and Colin had nothing to occupy them meanwhile except talk. "(I wish I could practice my job the same way,)" she said.

"(You have done it in simulation,)" Colin pointed out.

She sighed. "(Virtuals. In decent, ordinary space there is no proper substitute for the actual doing — let alone the region where we are bound.)" A crooked grin. "(But for that, we will only learn to swim by jumping into the water.)"

"(The simulations are as good as the ancient data allow.)"

"Och, aye," Kilbirnie said. "Nightmare good." Radiation, infalling matter, electromagnetic pulses, a gravitational field that waxed monstrous as you neared, until space itself, yes, time itself, got twisted beyond recognition. Not that any living creature could come so close and remain living. But the station from which the probes would operate must be guided into orbit. And later, who knew what might be required?

She laughed. "(I suppose I am impatient,)" she signed. "(However, I do think the simulations should include more sudden, unexpected fluctuations in things like the accretion disk and the electromagnetics.)"

"(I have suggested that, and been told it would be pointless, precisely because we know little about those events. Our data leave obscure the very causes of much of what was observed to happen.)"

"(I should think you Tahirians could deal with such matters more handily than us. Your sense for quantum mechanics, your instinct for coping with chaotic changes.)"

"(Like you, I look forward to our effort to learn more. But I think you humans have gifts of your own. Between us, we may accomplish what neither could do unaided.)"

"(We will try.)" Kilbirnie shivered in a rush of delight. "We will give it a bluidy great try." Impulsively, she stuck out her hand. Colin entwined ens with it. They shook partnership.

Presently Dayan called, "Enough already. I'm getting too tired. And Esther."

"It has been a long session," Kilbirnie agreed. "Aye, we'll take a break and a night's sleep. Strap in, folks, and hang on while I retrieve our beasties."

When everybody was secured, she tickled controls. The boat leaped. To and fro she jetted. "Harroo!" the pilot cried once. Robotic arms on the racks snatched missiles on the fly.

Having collected them, she whooped back to Envoy, made a contact that by rights ought not to have been as smooth as it was, and cut power. "Don't bother neatening inboard," she said. "We'd promptly make a new mess tomorrow. I'm for a cold beer and a hot shower." She led the way into the hull, through it, across to the forward wheel, and onto the railcar.

As usual, Nansen waited in the common room to receive them. He was conversing with the Tahirian they named Indira. Sundaram's close collaborator had come along on this visit to study the layout. It would influence the technical arrangements by which they hoped to communicate with the dwellers yonder.

The captain was not paying much attention. Perhaps for that reason, the semantician had begun to set forth elementary facts. "(... Do you realize how scant the earlier contact with the aliens was? We do not know if we can reestablish it on a regular basis, or at all. If we do, that will be the commencement of our true difficulties. We are ignorant of their nature . . .)"

Kilbirnie stopped in the doorway, so as not to rudely interrupt. Dayan caught up with her. They could read Indira's screen from there, hear ens voice and watch ens stance. "Yes," the human physicist said low, "I do believe the Tahirians of that time were afraid of what they might learn. It could overthrow the whole philosophical basis of the Eden they were building at home. That may have predisposed them to conclude that starfaring is a threat to everything."

Kilbirnie shrugged. "Myself, I've always felt grateful to Eve, that she succumbed. Eden strikes me as an unco dull place."

Nansen grew aware of them and turned on his heel. "Jean!" he cried.

Kilbirnie entered. "Dinna look so terrified, skipper, my jo. I was a good girl today. I flew strictly within the safety rules."

He frowned. "I followed your maneuvers on the 'scopes before I came down here. You pushed the envelope so hard that it crackled."

"Well, I need practice with more than routine. Wha' when we reach the black hole?"

His face went bleak. "Yes, what then?"

"Och, there I'll be vurra, vurra canny. It will make my recklessness for me."

"We'll have to talk about that."

"Richt the noo?" She stood before him, disheveled, sweaty, smiling her wide white smile. "Aweel, as you like. I can postpone my shower." She glanced at the others. "If ye will excuse us till dinnertime?"

Nansen reddened, harrumphed, and said quickly, "We don't seem to have anything more to do till tomorrow mornwatch. And I'm sure everyone would like to rest awhile before we meet this evening."

"Oh, yes," Dayan replied, flat-voiced. Her gaze trailed the captain and the pilot as they went out, side by side.

When she looked back, she saw Esther's parleur signaling. "(Why did those two leave abruptly?)"

"(They wish to be by themselves,)" Dayan said.

"(What is their motivation?)"

Sometimes speaking with a nonhuman through a device made frankness all too easy. "(She is a desirable person. He is the best man in five thousand light-years. Or maybe anywhere.)"