He had to be patient. If Mariama had survived, she would find a way to contact him.
Belatedly, it occurred to him to try the Left Hand. It responded. The vote Yann had spoken of had gone through in time: the Left Hand not only acknowledged his signal, it was willing to take instructions from him.
He had his Mediator construct a virtual replica of the familiar Blue Room console, and he placed himself before it. He merged Yann’s toolkit with the interface, and summoned the first simple menu of possibilities. For several seconds, he was too afraid to do anything but stare at the screen. Then he scribed a probe that would enter the far side and return as quickly as possible.
Minutes later, the echo came back to him. The surface layer of the far side, at least, was unchanged, populated by exactly the same mix of vendeks as they’d seen with the first experiment.
He tried a deeper probe. The result was the same: nothing had changed.
Tchicaya left the scape. He watched the horizon hopefully, sifting through the possibilities. The rebels had chosen not to scribe the Planck worms before mounting their attack on the ship. Perhaps they’d feared that they’d encounter more determined resistance from their opponents, if the annihilation of the far side was already playing out right before their eyes. A premature assault on the border would also have weakened the position of the remaining Preservationists, if the mutiny had been crushed. In any case, the fact that they’d felt a need to destroy the Rindler implied that the rebels were not confident that the process would be unstoppable once it had begun.
If the rebels hadn’t arranged for the loss of the ship to trigger the event immediately, there had to be some kind of timer counting down. If Mariama had got the shuttle free, she might have headed straight for the Right Hand, to pluck it out of the equation completely. If Birago had successfully corrupted it, the Right Hand would not take orders from her, and it was certainly more able to look after itself than the Scribe had been, dodging far larger shifts in the border. But Tchicaya doubted that it was equipped to defend itself from a determined assailant. The shuttle had more powerful engines; if it came down to brute force, she could probably bulldoze the Right Hand straight into the border.
If she reached it in time.
And if she was willing.
Three and a half hours after the loss of the Rindler, the border was transformed. Tchicaya didn’t perceive anything approaching; he merely saw the expanse of white light replaced in an instant by an opalescent gray. He turned just in time to catch sight of the edge of the change as it vanished behind him.
The sphere of the border was so vast that the true geometrical horizon was a billion kilometers away, but to his unaided vision everything beyond about a million kilometers occupied a single line, too narrow to resolve. After replaying the event, his calculations could not rule out the possibility that the change had swept by at lightspeed. That would have made it literally impossible to see coming, and then the delayed evidence of the fleeing edge would have given the impression that it was traveling at half its true speed, crossing the million kilometers he could distinguish in about six seconds.
He checked with the Left Hand. Being closer to the border, its field of view was smaller than Tchicaya’s, but its instruments left his senses for dead. It had tracked the change he’d witnessed, and judged it to be moving at the speed of light.
Not roughly, not nearly, but, to the limits of measurement, precisely the speed of light. Which meant that the Planck worms could not be pursued, let alone stopped.
The battle was over. The far side was lost.
Tchicaya caught himself angrily. The ability to move across the border at lightspeed didn’t guarantee the power to penetrate the far side at the same rate. For all he knew, he’d just seen nothing more than a variation on Branco’s surface-pinning effect.
He told the Left Hand to scribe another probe.
It couldn’t. The border had retreated.
Retreated how far? The Left Hand couldn’t tell him. How do you measure the distance to a featureless, immaterial plane of light? Once the border had slipped out of range of the particle beam of the stylus, the Left Hand had lost the ability to summon forth any kind of echo. It had scattered a small cloud of electronic fireflies, moving at about ten meters a second, to see when they were extinguished. So far, they all remained intact. It was no use tracking the brightness of the borderlight; each square meter of the border would seem dimmer as it retreated, but that effect was canceled out precisely by the fact that any particular instrument you aimed at it, with some fixed angle of view, would be taking in light from a larger portion of the border the further away it was. And there was no Doppler shift to reveal the velocity of retreat: the far side was being pared away, not pushed away, and the new, gray borderlight was being emitted from a succession of different surfaces, not a single moving source that could act as a clock.
The Left Hand had detected a microscopic lowering of the horizon against the backdrop of stars, which did prove that the Planck worms had corroded the far side into vacuum hundreds of thousands of kilometers away. But the line of sight from the Left Hand to the new horizon still only penetrated twenty or so meters below the surface where the border would normally have been; the growing crater could be as shallow as that limit, or it could be a million times deeper.
Tchicaya waited. The fireflies could still wink out at any moment. The Left Hand’s engines weren’t powerful, and it carried only a small reserve of fuel, but it could adapt to a shift in the border’s velocity of a few meters per second.
After ten minutes, nothing had changed. The fireflies were still visible. The border was outracing them.
That did not mean that there was no hope left. But to move the Left Hand faster than the fireflies, to have any chance at all of catching the border, he would need the shuttle.
He was useless on his own, now. It all came down to three Preservationists, and whether or not the hint of life in the far side had been enough to change their minds.
Tchicaya woke his father with a tug of the hand.
“What is it?” His father squinted at him blearily, but then he smiled and put a finger to his lips. He climbed out of bed and scooped Tchicaya into his arms, then carried him back to his own room.
He put Tchicaya down on the bed and sat beside him.
“You can’t sleep?”
Tchicaya shook his head.
“Why? What’s wrong?”
Tchicaya didn’t need to have the truth coaxed out of him. “I don’t want to get older,” he said. “I don’t want to change.”
His father laughed. “Nine isn’t old. And nothing’s going to change tomorrow.” It was his birthday in a few hour’s time.
“I know.”
“Nothing’s going to change for you, for years.”
Tchicaya felt a flicker of impatience. “I don’t mean my body. I’m not worried about that.”
“What, then?”
“I’m going to live for a long time, aren’t I? Thousands of years?”
“Yes.” His father reached down and stroked Tchicaya’s forehead. “You’re not worried about death? You know what it would take to kill a person. You’ll outlive the stars, if you want to.”