Falling free, each second laying more than a hundred new kilometers between her and a shrunken Sol, Envoy was about to enter the deep.

Her crew had not been aboard during the weeks of outward acceleration. There was no need of adding that to the unforeseeable stresses ahead of them. Two high-boost spacecraft overtook while the living cargo rested dreamless under brainpulse in weight-supportive tanks. Roused at rendezvous, they said their farewells and shuttled across to the starship.

It was the last valediction. Word from Earth would have taken an hour to reach them. After all the pomp and speeches, they agreed this was a mercy. Nevertheless it was lonely watching the other craft vanish into remoteness.

Here, at their distance from the sun's mass, space had flattened enough that the quantum gate could function. As nearly as instruments could tell, they were aimed close to Zeta Centauri, a marker on their way to the goal. It set the direction in which the energy from beyond space-lime would take them: speed, a scalar, becoming velocity, a vector.

They went quickly to their individual stations, a business rehearsed so often that now it was automatic and felt not quite real. In a sense, the feeling was right. Computers, circuits, machines would do everything. Humans only commanded, and at this hour the only commander was the captain.

His voice rang over the intercom: "Stand by for shield generation"  —  purely ceremonial, but ceremony had grown very needful.

A whirring followed as the main fusion plant came to full power, and ebbed away in steadiness. Eyes watching electronic viewscreens saw no change. The stars crowded brilliant against blackness, images reconstructed to hold fast though the wheel turned and turned. But gauges registered current through great superconducting coils, and magnetohydrodynamic fields sprang into being as a shell surrounding the ship at twenty kilometers' remove.

"All well," said the quasi-mind governing them.

"Stand by for zero-zero drive," called the master.

Muscles tightened, fists clenched, throats worked. No one feared. Crews had traveled like this, unharmed, for generations. Though Envoy's gate was the most capacious ever built, to bring her gamma factor to an unprecedented five thousand, robots had tested and retested it, had even taken animals along, proving utter reliability.

However, the gate was mighty because the journey would be.

"Go," said Nansen quietly.

Aft in the inner hull, switches flipped. Most of them were not material, but the quantum states of atoms. An eerie oneness awoke to existence. Between the two plates appeared a naked singularity, wherein the familiar laws of physics no longer held. Through it flowed a little of that underlying energy which the universe had not lost at the instant of its birth.

A little — enough to multiply the mass of ship and payload five thousand times and send her hurtling forward at a minuscule percentage less than the haste of light.

No sensation struck, except that viewscreens went chaotic, with swirls and flashes of formless hues. The energy entered everything equally, almost instantaneously, a quantum leap.

Notwithstanding, the power plant within labored close to its limit, while the governor of the shielding fields calculated and issued orders at a rate possible to nothing but a quantum computer. Space is not empty. Apart from stars and planets, it may be a hard vacuum by our standards; but matter pervades it, dust and gas — hydrogen, some helium, traces of higher elements — averaging about one atom per cubic centimeter in Sol's neighborhood, and cosmic rays sleet through it well-nigh unhindered. Had the ship rammed directly into this at her speed, radiation would soon have been eroding her; the crew would have been dead within the first few seconds. No material defense would have availed. Multimegawatts must go to work.

Guided and shaped by the boom forward, the fields were an envelope of armor. Laser beams, aimed forward, ionized neutral atoms, which the forces thereupon seized and sent as a wind that bore other stuff with it, flung aside and aft. In effect, a giant, streamlined shape flew through the medium, cocooning the vessel inside.

X-rays did pierce it from dead ahead, made fiercer by Doppler effect, but no more than wheel and hull could ward off. Otherwise aberration caused them to pass through an aftward cone, attenuated both by distance and by lengthening of their waves. Well did Envoy guard her people. Yet the battle was incessant and the power requirement high. Meanwhile she must fill her capacitors with still more energy.

Thus did she run, for some two hundred astronomical units, far out into the Oort cloud of comets. Observers orbiting Sol registered the time as a bit more than an Earth day. To her and those aboard her, it was slightly under twenty seconds. And both were correct. Her relativistic time dilation was the inverse of her gamma factor, and just as real.

Then the loan fell due. The quantum field collapsed, the high-energy state ended, she moved on trajectory no faster than she had done before, about 150 kilometers per second; for her, lengths and passages of time were the same as they had been at home. Like the acceleration, the deceleration happened too swiftly and pervasively to be felt.

She must repay her loan in full. She had done work, moving interstellar matter aside, moving herself farther from Sol. The collapsing field would have reclaimed the deficit from her atoms, disastrously, were she not prepared. As it was, the energy in her capacitors flowed into the field and satisfied. The net expenditure had been precisely zero.

"Jump one!" cried the captain, as was traditional.

It was a gesture, not repeated. Already, in a fractional second, the gate had reopened and Envoy was again running on the heels of light.

The optical system soon compensated, and viewscreens once more displayed the stars. Three showed the heavens weirdly distorted by speed, for purposes of monitoring the flight. The rest took photons captured in the brief intervals between jumps and let computers generate an image shifting evenly from point to point. Thus far the scene had scarcely changed. A few light-days, a few light-years, are of little consequence in the vastness of the galaxy. But Sol dwindled fast from a small disk to the brightest of the stars, and second by second it diminished further, as if it were falling down a bottomless black well.

Nansen and Dayan stood in the command center, looking. They belonged together in this first hour, captain and physicist. Theirs were the intuitions, instincts, judgments that no artificial intelligence could ever quite supply. Did it seem best to abort the voyage, they would decide.

They found no reason to. Around them instruments gleamed and gave readings, the ship murmured impersonally, a breeze pretended to blow off a field of new-mown grass. They watched their sun waning, and silence was upon them.

Nansen broke it with a whisper. ". . . el infinito Mapa de Aquel que es todas Sus estrellas."

"What?" asked Dayan, almost as softly.

"Ay —" He came out of his reverie and shook himself, like a swimmer climbing ashore. "Oh. A poem that crossed my mind. 'The infinite map of the One who is all His stars,' By Borges, a twentieth-century writer."

She regarded the lean, grave face before she said, "It's lovely. I didn't know you were such a reader."

He shrugged. "There is much time to fill, crossing space."

"And it makes a person think, doesn't it?" She stared out at the cold galactic river. "How insignificant we are to everything except ourselves."

"Does that trouble you?"

"No." The red head lifted defiantly. "Ourselves are what we have to measure everything by."

"I am not so sure of that. The fact that there are countless things we will never know, and many that we could not possibly know, does not mean they do not exist — only that we cannot prove it. I am a philosophical realist."

"Oh, me too. No physicist today takes seriously any of that metaphysics that sprang up like fungus around quantum mechanics in its early stages. I meant just that we're tiny, an accident, a blip in space-time, and if and when we go extinct it won't make, we won't have made, a raindrop's worth of difference to the cosmos."

"I am not so sure of that, either."

"Well, your religion —" She broke off, half embarrassed. "I'm not observant of what's supposed to be mine."

Nansen shook his head. "If anything, what faith I have comes from this material universe. It doesn't seem reasonable to me that something so superbly organized, its law reaching down beneath the atom, out beyond the quasars, through all of time, that it would throw up something as rich as life and intelligence by chance. I think reality must be better integrated than that, and we are somehow as much a part of it and its course as the galaxies are." His smile quirked. "At least, it's a comforting thought."

"I guess I'd like to share it," Dayan said, "but where's the actual evidence? And we don't need comforting, or ought not to. Whatever we are, we can be it in style!"

He considered her. "Yes, you would feel like that."

She met the look. "You would, too, regardless," she answered.

For several pulsebeats they stood mute, unmoving.

"I should get back to my laboratory," she said quickly. "Everything seems in order here, and you remember I have some experiments going. At our gamma factor, who knows what we might detect?"

Journey commenced, the rest of the expedition had, in an unspoken mutuality, sought the common room. Together they sat watching Sol recede. In a few more hours of their time, it would no longer be the dominant star. In a day and a night of their time, thirteen and a half years would pass on Earth.

Sundaram rose from his chair. "I believe that suffices me," he said. "If you will pardon me, I shall retire."

"For a nap?" Kilbirnie asked, as lightly as she was able.

"Possibly," he replied in the same spirit. "Or possibly I can pursue an idea a trifle further." He went out.

Brent squinted after him. "Good Christ," the second engineer muttered, "is he anything but a thinking machine?"

"Much more," Zeyd told him sharply. "I have taken the trouble to become acquainted."

Brent lifted a palm. "No offense meant. If he doesn't care for women, it makes things easier for me, if he doesn't make a pass at me." He saw frowns and tightened lips. "Hey, sorry, just a joke."

Yu stood up. "I think we would be wise to inspect the recycler systems," she said.

"Why, is there anything to fear?" Zeyd wondered.

"No. I am confident they have themselves well in hand. However, the final responsibility lies with my department," — responsibility for the nanotechnics and processings that turned waste back into fresh air, pure water, food, and the luxuries that were almost as vital. "One more go-through, now that we are under zero-zero, will secure us more firmly in our teamwork."

"Oh, all right," Brent said.

"Actually, a welcome diversion." Zeyd made a gesture at the awesome-ness in the screen. As the biochemist, he was involved.

"Should I come, too?" asked Mokoena, biologist and physician.

"No need, unless you wish to," said Yu. She led Brent and Zeyd out.

Mokoena stayed. "That was neatly done," she told those who also remained. "She defused what could have become an awkward situation."

Cleland stirred, cleared his throat, and spoke tentatively. "Do you mean Al might have, ah, lost his temper? I don't think so. He's not a bad man."

"I didn't say he was," Mokoena answered.

"Besides," Ruszek put in, "I think what Wenji wants is to give her group something to do. The sooner everybody's busy, the better. Sitting and gaping at... this ... is no good."

Mokoena chuckled. "As for that, we can trust our captain to have some ritual planned for our first supper."

Ruszek shrugged. "Probably. He didn't approach me about it."

Kilbirnie jumped to her feet. "Meanwhile, we do jolly well need a break," she exclaimed. "Who'd like a hard game of handball?"

Ruszek brightened. "Here's one," he said. Side by side, they left for the gymnasium.

Cleland started to follow but sank back down. "Wouldn't you care to join them?" Mokoena asked.

His glance dropped. "I'd be too slow and clumsy."

"Really? You've handled yourself well in some difficult places."

He flushed. "That was . . . competing against nature . . . not people."

"You mustn't let jealousy eat you, Tim," she said gently.

His head jerked up to stare at her. "What do you mean?"

"It sticks out of you like quills." She leaned forward and took his right hand in hers. "Remember what the captain told us on our shakedown. We cannot afford hostility or bitterness or anything that will divide us."

"I suppose we ... should have made . . . our personal arrangements before we embarked."

"You know that wasn't practical. Especially when relationships are sure to change as we go."

"You and Lajos —"

"It is friendly between us," she said. "But it's not binding on either one." Her smile offered no more than kindliness, a kindliness without urgency or need to be anything other than itself.