Schild’s Ladder

crinkling that allowed the border to increase in area while the volume of novo-vacuum itself was shrinking?—?this left little room for doubt about which vacuum was being whittled away to produce the particles they were seeing. The thing she had always thought of as an elegant piece of whimsy?—?as charming and impractical as a mythical beast that might be bioengineered into existence, and kept alive briefly if it was pampered and protected, but which could never have lasted five minutes outside its glass cage?—?was now visibly devouring its ancient, wild cousin. She had summoned up, not a lone, defenseless exile from a world that could never have been, but the world itself?—?and it was proving to be every bit as autonomous and viable as her own.

Rainzi addressed her, gently but directly. “If the station is destroyed, we all have recent backups en route to Viro. What about you?”

She said, “I have my memories back on Earth. But nothing since I arrived here.” The five years she’d spent among the Mimosans would be lost. It had still happened. She had still lived through it all. It would be amnesia, not death. But if that argument had been enough to let her step willingly into the cul-de-sac she inhabited now, she wasn’t sure she could push it far enough to reconcile herself to the greater loss. She had finally become someone new, at the station?—?someone different enough from her old self to be here now, beside the Mimosans. But the Cass who had steeled herself to leave the solar system for the very first time would wake from her frozen sleep unchanged, to learn that the emboldened traveler she’d hoped to become was dead.

“I don’t know how to help you make peace with that,” Rainzi said. “But I can only think of one way to make my own peace with the people we’ve endangered.” Mimosa was remote from the rest of civilization, but the process they’d begun would not burn itself out, would not fade or weaken with distance. With vacuum as its fuel, the wildfire would spread inexorably: to Viro, to Maeder, to a thousand other worlds. To Earth.

Cass asked numbly, “How?”

“If we can see a way to stop this,” Rainzi replied, “then it doesn’t matter that we can’t enact it ourselves, or even get the word out to anyone else. We can still take comfort in uncovering the right strategy. I know we have certain advantages?—?in the time resolution with which we’re seeing the data, and in being the only witnesses to this early stage?—?but on balance, I think the combined population of the rest of the galaxy constitutes more than an even match. If we can find a solution, someone out there will find it, too.”

Cass looked around at the others. She felt lost, rootless. Not guilty, yet. Not monstrous. The Mimosans would all wake on Viro, missing a few hours' memories but otherwise unscathed, and though she’d robbed them of their home, they’d understood the risks as well as she did when they’d chosen to conduct the experiment. But if the loss of the Quietener and the station was something she could come to terms with, it was still surreal to extrapolate from her own few picoseconds of helplessness to the exile of whole civilizations. She had to face the truth, but she was far from certain that the right way to do that was to hunt for a solution that would at best be a plausible daydream.

Darsono caught her eye. “I agree with Rainzi,” he said solemnly. “We have to do this. We have to find the cure.”

“Livia?”

“Absolutely.” Livia smiled. “Actually, I’m far more ambitious than Rainzi. I’m not willing to concede yet that we can’t stop this ourselves.”

Zulkifli said dryly, “I doubt that. But I want to know if my family will be safe.”

Ilene nodded. “It’s not much, but it’s better than giving up. I’m not bailing out just to spare myself the sense of being powerless?—?not while data’s pouring in, and we can still look for an answer.”

“The danger doesn’t seem real to me,” Yann admitted. “Viro is seventeen light-years away, and we can’t be sure that this thing won’t snuff itself out before it even grazes the shell of the Quietener. But I would like to know the general law that replaces the Sarumpaet rules. It’s been twenty thousand years! It’s about time we had some new physics.”

Cass turned to Bakim.

He shrugged. “What else are we going to do? Play charades?”

Cass was outnumbered, and she wanted to be swayed. She ached to get her hands on even the smallest piece of evidence that the disaster could be contained, and if they failed, it would still be the least morbid way to go out: struggling to the end to find a genuine cause for optimism.

But they were fooling themselves. In the few subjective minutes left to them, what hope did they have of achieving that?

She said simply, “We’ll never make it. We’ll test one hunch against the data, find it’s wrong, and that will be it.”

Rainzi smiled as if she’d said something comically naive. Before he spoke, Cass recalled what it was she had forgotten.

What it was she had become.

He said, “That’s how it will seem for most of us. But that shouldn’t be disheartening. Because every time we fail, we’ll know that another version of ourselves will have tested another idea. There will always be a chance that one of them was right.”

PART TWO

Inhabited Space

Only a small proportion of all systems are shown. Shaded systems have been lost behind the border as Tchicaya arrives on the Rindler, 605 years after Mimosa.

Chapter 4

By choice, Tchicaya’s mind started running long before his new body was fully customized. As his vision came into focus, he turned his gaze from the softly lit lid of the crib to the waxen, pudgy template that he now inhabited. Waves of organizers swarmed up and down his limbs and torso like mobile bruises beneath the translucent skin, killing off unwanted cells and cannibalizing them, stimulating others to migrate or divide. The process wasn’t painful?—?at worst it tickled, and it was even sporadically sexy?—?but Tchicaya felt an odd compulsion to start pummeling the things with his fists, and he had no doubt that squashing them flat would be enormously satisfying. The urge was probably an innate response to Earthly parasites, a misplaced instinct that his ancestors hadn’t got around to editing out. Or perhaps they’d retained it deliberately, in the hope that it might yet turn out to be useful elsewhere.

As he raised his head to get a better view, he caught sight of an undigested stretch of calf, still bearing traces of the last inhabitant’s body hair and musculature. “Urrggh'. The noise sounded alien, and left a knot in his throat. The crib said, “Please don’t try to talk yet.” The organizers swept over the offending remnant and dissolved it.

Morphogenesis from scratch, from a single cell, couldn’t be achieved in less than three months. This borrowed body wouldn’t even have the DNA he’d been born with, but it had been designed to be easy to regress and sculpt into a fair approximation of anyone who’d remained reasonably close to their human ancestors, and the process could be completed in about three hours. When traveling this way, Tchicaya usually elected to become conscious only for the final fitting: the tweaking of his mental body maps to accommodate all the minor differences that were too much of a nuisance to eliminate physically. But he’d decided that for once he’d wake early, and experience as much as he could.