they had built their team, and its numbers bolstered their loyalty in a way that mere reason never could.
Near the Null Line, Ruz and his apprentices were working on their new clock, tinkering with the mechanism as they calibrated it against a cycling pair of shomal-junub stones. Zak had set them a wildly ambitious target: to create something small enough for a traveler to carry anywhere in the Splinter, oblivious to the varying weights and accurate enough to be trusted for thirty-six shifts without recalibration. After trying out many unwieldy designs, they had devised a system in which two spiral coils of metal ribbon were joined at their centers to small shafts. The first and larger of the coils was tightened by turning its shaft with a lever, and then the force as it unwound was eked out slowly and employed to feed a gentle, to-and-fro rocking of the other coil’s shaft. Rendering this complex mechanism perfectly regular was a serious challenge, but the team never seemed to be short of new ideas to try, and each refinement so far had improved on the last.
Ruz had been a metalworker for most of his life. It had taken Roi more than a dozen shifts to recruit him, but he had later admitted that the instant he’d seen Roi’s “Rotator”—her contraption for demonstrating the Splinter’s spin—he had been hooked in equal measure by a fascination with the idea that the world could be secretly turning, and a conviction that he could do a far better job at making the kind of gadgets needed to quantify that motion. Happily, his conviction had turned out to be entirely justified.
Roi drifted past the clockmakers and landed against the wall, close to the point where Tan was talking with a small group of students. “What is natural motion?” he asked. “Looked at closely, and in the absence of spin, it seems as if a weightless stone is trying to follow a straight path. Yet over large enough distances, that path can curve around into a circle, or other kinds of curves. What’s happening?” He lifted up a complicated patchwork he’d made by gluing together dozens of fragments of skin. “See this line, marked across this surface?” He indicated a path he’d dyed in ink. “On every small piece of the surface, it’s a straight line. But the line as a whole isn’t straight; it can’t be, because the surface itself isn’t flat. So how can we determine exactly which paths can be made by small, straight lines joined together in this way? That will depend on the way the parts of the surface are connected to each other. We need a precise, mathematical expression of the nature of that connection, in order to understand which paths are as straight as they can be, given the geometry of the surface.”
Roi listened closely. She, Zak and Ruz had lured Tan away from the sign-age team where he’d honed his geometrical skills. Calculating distances through the tunnels of the Splinter had given him both an extraordinary facility with numbers and a powerful sense of how they could be used to analyze paths, shapes and motion.
“Keep in mind,” Tan continued, “that there is one ingredient in the idea of natural motion that doesn’t show up when we study a surface like this. Zak has argued that the natural path for any stone you throw from a given point depends, not just on the direction you throw it, but also upon its speed. The natural path of the Splinter appears to be a circle, but an object that starts out on that circle and travels in the same direction as the Splinter will still follow a path with a different shape if it’s moving faster or slower than the Splinter. So we need to find a way to incorporate that into our geometrical scheme. We need to merge the idea of
Roi had to make an effort to tear herself away. She had heard Tan explain these ideas many times, but on each occasion the concepts became a little clearer, a little bit more precise. If he ever reached the point where they were defined with sufficient mathematical rigor to allow her to start making calculations, she hoped she could find a way to merge them with Zak’s other principle—that the true weights everywhere summed to zero—and then she might finally be able to start mapping the possibilities for the Splinter’s past and future.
She clambered across the wall to the crevice where Zak was resting. She tapped the adjacent rock gently, and after a moment a single claw emerged from the crack.
“It’s Roi,” she said, “I’ve brought you some food.”
“Thank you.” Zak slid out on to the wall, awkwardly. Roi opened her carapace and took out a bundle of food. She’d spent half the shift collecting it, but she did not begrudge the effort. Zak was old, his body was failing, but she had no intention of letting him starve to death.
Zak ate slowly, in silence. Roi no longer asked him what hurt and what didn’t; she gathered that almost everything did.
When he’d finished, he surveyed the activity in the chamber with a satisfied air. Roi could see the meal dissolving smoothly inside him, unhindered by the obstructions she’d noticed the last few times. Clearly the rest had done him some good.
“How are you finding things on your travels?” he asked.
“What do you mean?” She’d returned from the last recruiting expedition with two young students, but that had been several shifts ago, and she’d reported the result to him then.
“How do people think of us? Word must have spread out from the Calm by now, that there’s a new team here, doing a new kind of work.”
“Ah.” It was a good question, but a difficult one to answer. “I wouldn’t say that there’s any particular resentment directed against us. Nobody likes having their team-mates taken, but recruitment is recruitment, it’s a fact of life.”
“And work is work?” Zak pressed her. “The mere existence of a team is its own justification?”
Roi replied cautiously, “It seems that way. Most people don’t consider themselves experts in the history of the Splinter, to the point of declaring ‘There has never been a team like that before’. Work is whatever a group of people do, and most of us take it for granted that what other teams do is useful in some way. There might be only five or six jobs that literally everyone knows about and understands, but that doesn’t mean people are hostile or suspicious toward all the rest.”
Zak pondered this. “I’ve been wondering at what point we’ll need to let some of our own members get poached.”
Roi was startled. “Can we afford that? Our numbers are still very low.”
“Can we afford not to?” Zak replied. “It’s not just a matter of being sure we play the game, being sure our existence is accepted. It would also be of value if some of our ideas could spread outside the team itself. Almost every child learns writing and simple arithmetic; they’re parts of the culture that have managed to move beyond the specializations where they originated. Imagine if the facts about weight and motion could acquire the same status.”
Roi could see where this was heading. “So by the time the next division of the Splinter is imminent, everyone will have at least a basic understanding of what’s going on. It won’t be necessary to try to educate them from scratch.”
“Is that too ambitious?” Zak wondered.
“I don’t know. Tell me when the next division is coming.”
Zak emitted a sarcastic rasp. “I have a feeling you’ll know that before I do.”
“Don’t count on it.” In truth, the idea of being able to predict the event still seemed almost as strange and metaphysical a prospect to Roi as the thing itself.
“When is the next overview meeting?” Zak asked.
“Two shifts from now.”
“I think I’ll attend.”
Roi was pleased. “It will be good to have you there. You’ve been away for too long.” She hadn’t been close to anyone near the end of their life before, and she was never sure what to expect. Zak’s strength came and went, and every time it declined she was afraid he was dying, but a few shifts’ rest, some good news about the team, and a problem worth thinking about were often enough to revive him. He’d never travel all the way to the garm-sharq edge again, but he might survive at the Null Line for dozens more shifts.
She bid him farewell, and launched herself across the chamber to the point on the web where her own equipment was set up. Every shift, she counted a few cycles of the three periodic motions to see if anything had changed in their relationship. Once Ruz’s clock was declared trustworthy as a standard in its own right she’d start using it to measure the absolute durations of the cycles, but until then she was content to record the ratios between them.
She set everything in motion and then watched patiently, counting the passage of the cycles using a trick she’d picked up from Gul, a recruit who’d worked in a storage depot: sliding a series of stones threaded on wires, rather than trusting everything to memory or wasting precious skin by making a scratch for each event. Though all three motions slowly diminished over time—however thin the air the stones were moving through, however well- greased the pivots on the Rotator’s spinning bar—the periods she was measuring were unaffected, and as long as
