“So try it again,” his father insisted.
Tchicaya complied.
“I’ve made a mistake,” he said. He erased the second ladder, and repeated the construction. Again, the second copy of the arrow at the end of the path failed to match the first.
“I don’t understand,” Tchicaya complained. “What am I doing wrong?”
“Nothing,” his father assured him. “This is what you should expect. There’s always a way to carry the arrow forward, but it depends on the path you take.”
Tchicaya didn’t reply. He’d thought he’d been shown the way to safety, to persistence. Now it was dissolving into contradictions before his eyes.
His father said, “You’ll never stop changing, but that doesn’t mean you have to drift in the wind. Every day, you can take the person you’ve been, and the new things you’ve witnessed, and make your own, honest choice as to who you should become.
“Whatever happens, you can always be true to yourself. But don’t expect to end up with the same inner compass as anyone else. Not unless they started beside you, and climbed beside you every step of the way.”
Tchicaya made the globe vanish. He said, “It’s late. I’d better go to sleep now.”
“All right.” His father stood as if to leave, but then he reached down and squeezed Tchicaya’s shoulder. “There’s nothing to be afraid of. You’ll never be a stranger, if you stay here with your family and friends. As long as we climb side by side, we’ll all change together.”
“Tchicaya? Can you hear me?”
It was Mariama.
“Loud and clear,” he said. “Are you all right?”
“That depends what you mean by me. My Qusp is fine. Parts of my Mediator got fried; I only have a short-range IR link left. My body’s not a pretty sight, but it’s recovering.”
The signal was coming to him via the Left Hand; she’d freed the shuttle and gone there in person. The long-range transceivers in both the module and the shuttle must have suffered irreparable radiation damage, which said something about the likely state of her body.
“What about the others?”
“Wael and Alejandro received similar exposure. They helped me get the shuttle unglued, but they weren’t interested in sticking around, with no mod cons and such poor company. Birago’s body seemed to be in better shape than mine, but the builders halted his Qusp, so he’s as good as departed. When I left, the other rebels were all in a bad way; some of their bodies had reverted to undifferentiated goo, and even in the ones that were still intact and breathing, I’d be surprised if their minds have survived the repair process.”
She was probably right; the bodies would make liberal use of apoptosis to kill off radiation-damaged cells, and there was no reason for them to treat neural tissue any differently.
Mariama said, “I went to the Right Hand first, but it had already scribed the Planck worms. It wasn’t pursuing the border down, but I gave it a nudge in the opposite direction, too fast for it to reverse. If we find some use for it, I could go and drag it back, but I’m hoping the Left Hand will be enough.”
“It will have to be.” Nothing they did to the Right Hand would render it trustworthy.
“Branco told me about the toolkit Yann gave you, while he was cutting us loose, but I didn’t have time to get a copy myself. The simplest thing might be if you send it to me now, before I go chasing the border.”
“What?” Tchicaya stared at the red-shifted stars above the horizon, checking the view for any sign that he’d departed from reality and was hallucinating this entire encounter. “Why would that be simplest? You’re coming to get me, aren’t you?”
“That would be an awful waste of fuel. You don’t need to be here, physically.”
Tchicaya was silent for a moment. She was right about the fuel, but he couldn’t accept what she was proposing.
“That’s not true,” he said. “If I stay out here, I’m going to lose radio contact, eventually. From sheer distance in the long run, but if the border has taken on a complicated shape, I might lose my line of sight much sooner.”
“Then give me the key to the Left Hand. With that, and the toolkit, I can manage everything.” She sighed. “Don’t be precious about this. I don’t like the idea of leaving you to drift away, but there are more important things at stake here. The time and the fuel I used fetching you could make all the difference to the far side.”
Tchicaya felt a flicker of temptation. He could wash his hands of everthing, and wake beside Rasmah on Pfaff. Mariama was being perfectly logical; time was against them, and apart from the secondhand skills that he could easily sign over to her, he was superfluous.
He wanted to trust her. Hadn’t she earned that? They’d had no end of differences, but she had always been honest with him. It seemed petty and mean-spirited to keep on doubting her.
The trouble was, he didn’t trust his own motives. Thinking the best of her would be the perfect excuse to absolve himself of all responsibility.
He said, “I’m not handing you anything. If you care so much about the far side, you’d better come and get me.”
Mariama remained seated at the front of the shuttle as Tchicaya clambered out of the airlock. He nodded a greeting, and tried to smile. Her Exoself would be discouraging her from doing anything to interfere with her body’s healing, by means both gentler and more precise than a blanket of agony; extrapolating from the raw pain of the minor burns he’d willingly experienced as a child was absurd. Still, the sight of her weeping, blistered skin made his guts tighten.
He said, “Hitchhiking in space isn’t so bad. I’ve waited longer for a ride, on land.”
Mariama replied through the IR link. “Try showing more flesh. That always works wonders.”
On their way back to the Left Hand, Tchicaya received the first good news he’d heard since the moratorium vote. The horizon had stopped falling. The Left Hand was no longer seeing new stars creeping into view.
That in itself didn’t fix the depth of the lost region everywhere, but the particular geometry was suggestive. The new horizon was exactly where it would have been if the Planck worms had failed to penetrate the signaling layer, where the vendek population changed abruptly, a hundred kilometers into the far side.
As they approached the Left Hand, the news became even better. The fireflies had finally begun to vanish, and the timing of their deaths confirmed the best possible scenario: the border had retreated to the signaling layer, and no further.
Tchicaya was elated, but Mariama said, “Don’t assume this is the new status quo. Birago wasn’t exactly confiding in me toward the end, but if what he’s done here bears any resemblance to the work I was involved in with Tarek, the Planck worms won’t have given up at the first obstacle.”
“Meaning what?”
“They’ll mutate. They’ll experiment. They’ll keep on varying themselves, until they find a way to break through.”
“You knew how to do that? You had it all worked out?”
“No,” she admitted. “But as soon as you showed us the vendeks themselves, they provided an awful lot of inspiration. Tarek and I didn’t pursue that, but don’t expect Birago to have passed up the opportunity.”
They docked with the Left Hand, and carried it down to the point where the fireflies were disappearing.
Regaining alignment with the border took almost an hour, as a cycle of increasingly delicate adjustments brought the stylus into range. Once that was achieved, Tchicaya scribed a series of probes that would spread out laterally as well as moving straight in, improving their chances of gaining a comprehensive picture of the Planck worms. Unsurprisingly, now that the signaling layer was infected with Planck worms and exposed to vacuum, it was no longer vibrating, no longer tapping out primes. Tchicaya longed to discover the mechanism that had driven it, but he had to stay focused; trying to dissect the far-siders' ruined SETI equipment — if that was what it was — had to take second place to dealing with the plague the beacon had been unable to deter on its own.