Roi passed the time by checking Kem’s results. She did the work scrupulously, but it scarcely demanded her attention; it was like walking now, pure instinct. These were not new template calculations, replete with symbols for unspecified values; rather, she and Kem were feeding a range of numbers into existing templates, making earlier, abstract computations concrete.
Kem was, in effect, mapping out dozens of possible futures for the Splinter, attempting to distinguish the safe paths from the hazardous. Shuffling the numbers in a single case was a straightforward process, but it was impossible to prepare for every combination of circumstances that might arise along their journey. Roi was almost certain that they had found the true geometry, but they still could not predict how the strength of the wind would change as they moved out from the Hub; its speed was dictated by the curvature of space-time, but its density was not. Anticipating the Wanderer’s behavior was even more difficult. Though it followed a comprehensible orbit for short stretches of time, its motion was subject to unpredictable changes, and only some of these could be clearly linked to its visible eruptions.
Nobody could understand the Wanderer’s nature. It appeared to be a ball of wind and light, but what could hold such a thing together? Nothing in the long run, apparently, since the wind and light were spilling out ever more violently the closer it came to the Hub. Whether the old stories of the Splinter’s origins were true or not, the Wanderer was fragmenting in a very different way; instead of being torn brutally in half in one cataclysmic moment, it was forever being stripped of small portions. If the Splinter’s mythical parent really had divided, that would have eased its plight for a very long time, halving the greatest of the weights until some ancient Jolt, or some generation-spanning drift toward the Hub had eventually increased them. The Wanderer’s losses seemed to make no difference, as if each small excision only gave it a chance to offer up something more, like a fast-growing crop eager to be pruned.
Haf and the others kept bringing food. Sometimes Roi caught herself trying to guess who among them were her children, but even when that urge passed she was surprised at the strength of her feelings toward them all. Her sense of duty had always been directed toward her team-mates; of course she had never been indifferent toward hatchlings, and would have aided any child she found in need, but the idea that the well-being of the next generation was as important as the completion of her next shift had always been a remote one, with little emotional force and even less need to be acted upon. Eggs hatched themselves, and the hatchlings found teachers; this didn’t require any attention from her. The clearest lesson on the matter she had received from her own teachers had concerned the need to practice contraception with sufficient diligence to avoid playing her part in bringing on a famine.
Now the sight of Haf, Pel, and Tio brought a warmth to her mind that was as strong as the buzz of cooperation. The hope she felt at the prospect of navigating the Splinter to safety was still, in part, the same kind of longing for a successful shift that she had known all her life, but that familiar emotion was increasingly overlaid with a compelling sense of what it would mean for the ultimate beneficiaries. The thought of her own premature death, of Gul’s, of Ruz’s, of all her ‘team-mates’, was dismaying, and more than enough to drive her, but the extraordinary idea that they could carry the hatchlings into a transformed world where this danger would finally lie completely behind them was imbued with both more urgency, and more prospective joy, than anything else she had ever contemplated.
Leh, who watched for light-messages from the junub edge, came to Roi with a written transcript. Ruz’s team had measured a small increase in the Splinter’s orbital period. It was tiny, but it stood out above the usual variations due to uncertainty in their observations and the imperfections of their clocks.
Roi waited three more shifts for the next report to arrive, before letting herself believe it. The second set of timings confirmed the earlier result: the Splinter was moving, drifting outward very slowly.
She sent the news on to Neth and Bard, then asked Kem to tell the other theorists. In no time at all there was a riot of delighted chirps coming to her from the surrounding tunnels.
When Kem returned, Tan was with her.
“It’s good news,” he said, “but I’m worried by how slowly we’re moving. It doesn’t give us much flexibility if we find ourselves in a dangerous situation.”
Roi concurred. “Bard and Neth understand that. They’ll make the new tunnels their priority now.”
Kem said, “If the Wanderer continues to behave as it has been, I believe that with three tunnels we’d have enough control over our ascent to pass through the Wanderer’s orbit on the opposite side of the Hub. The problem will be if that orbit shrinks rapidly without warning.”
“There’s something else we might need to consider,” Tan said. “One of my recruits, Nis, came to me two shifts ago with a new idea about the Wanderer. I don’t know how seriously we should take it, but he’s working on the details, trying to make it more precise.”
“What’s the general idea?” Roi asked.
“The strength of rock is what holds the Splinter together,” Tan said. “But the Wanderer doesn’t seem to be made of rock. So why doesn’t it simply fall apart from the usual weights? Spinning in different ways from the Splinter won’t do the trick. Without strength of some kind, it ought to be smeared all along its orbit by now.”
“So what kind of strength can it have?” Kem asked.
“Geometry,” Tan replied. “The same thing that keeps us close to the Hub holds the Wanderer together. But now the Hub and the Wanderer’s geometry are fighting each other for the Wanderer’s wind and light.”
Roi allowed herself a moment of pure exhilaration. It was a beautiful, audacious proposition. Who ever said the Hub was the only object in the void that could be wrapped in curvature? It might be the strongest thing in sight, powerful enough to twist the Wanderer’s path around it, but that didn’t mean the Wanderer itself was a mere passive follower of geometry, as the Splinter seemed to be. Why couldn’t it carry its own curvature? The Hub had the glory of the entire Incandescence, but the Wanderer, at least for now, held on to its own portion of wind and light. The two were alike, one smaller, one greater.
Unfortunately, if this elegant solution to the mystery was true, it changed everything. If the Wanderer was wrapped in space-time shaped as it was around the Hub, then in turn the geometry around the Hub itself could not be described perfectly by the rotationally symmetrical solution that she and Tan had found. The presence of the Wanderer was like a dent hammered into a smoothly curved sheet of metal; it could be ignored from afar, but the closer you came to it, the more significant it would be.
Kem appeared dazed. “Two Hubs fighting? We need the geometry for two Hubs fighting?”