While Roi had paced, Ruz had been still, but now she heard him shifting, consulting his clock. “Zak?” he called. “It’s halfway through the dark phase!”
A few heartbeats passed, then the reply came back, “I know.”
Roi said, “We should have tied a rope around him. Then if he cut it too fine we could have just dragged him down.”
Zak hadn’t taken the light machine, because of its weight, but they had never imagined that such a device would be available. Ruz had made three clocks that could easily be read by touch, and Zak had practiced in total darkness setting up the most important instrument, the one that would allow him to measure the passage of an object across his field of view. Once that was in place, then so long as there was a beacon worth aiming at, he only had to be able to time the moments when it passed behind a series of metal wires. However dim or bright an object might be, whatever the color of its light, you always knew when it passed behind metal.
“An arc of light?” Roi said. “Do you know what that could be?”
“No,” Ruz replied. “But be patient. We’ll have the whole journey back in which to interrogate him. In fact, we should extract every detail and write it all down, so if the Splinter sinks back into the Incandescence and never leaves it again, we’ll have a record of what lies beyond.”
Roi struggled to imagine what it could be like, looking out into the void. “If the Splinter really did break in two, long ago, do you think we could ever find the other half? Ever see it, even if we couldn’t reach it?”
Ruz pondered the question. “It’s hard to know how far away its orbit might be. Until we know, in spans, how far away the Hub is, it’s difficult to quantify anything else. At the moment, we’re not even sure that our orbit is ‘size eight’, let alone what that would mean in terms of actual distances.” He paused, then called out, “One-quarter of the dark phase remaining! Zak, you need to move now!” It had taken Zak almost a quarter-phase to ascend through the crack, and though it would be easier coming down they needed to keep a healthy margin of safety.
Roi waited for his reluctant assent.
There was nothing.
“Zak?” She pressed her body against the rock, straining to hear anything, a word or a footstep. “Zak?”
She climbed up into the mouth of the crack. “I’m going up there. Something’s happened to him, I need to bring him back.”
Ruz said, “If the void’s harmed him, it will do the same to you.”
“You know what his health is like! He’s been sick even back at the Null Line. The effort of the climb would have been enough to weaken him.”
“When we planned this trip,” Ruz insisted, “we all agreed that only Zak would take the risk—”
Roi seethed with frustration. He was right, they had agreed, but she didn’t care. She said, “I’m not going to waste time arguing.”
She clambered up the inside of the crack as quickly as she could, forcing herself to ignore the instinctive urge to feel her way slowly through the darkness. The rock was sharp in places, and slippery with weeds, but she kept her footing, and kept advancing. She didn’t try to judge the distance or the passage of time, she just willed herself forward.
When a hint of light appeared ahead, she made no effort to make sense of it. Moments later, she tumbled on to the surface of the Splinter.
A band of light was wrapped across the blackness of the void, an arc that stretched from a point high above the rock and swept around a quarter-circle before the Splinter interrupted it. The color of the light varied smoothly across the band from inner to outer rim; within it, small points of brightness slowly drifted, changing color as they moved. Roi looked away; the spectacle was baffling and hypnotic, but this was not the time to sink into the morass of questions that it posed. The illumination it cast on the rock around her was weak and shallow, barely more than that cast by the light machine, but she had no trouble spotting Zak.
She ran to him, and drummed directly on his body. “What happened? Can you move?”
He stirred feebly, but there was no reply.
“Climb on to my back. Can you do that?” She placed herself beside him and flattened herself against the rock.
Nothing. She waited a few heartbeats, but he didn’t move.
“All right. I’m going to try to lift you. Relax your grip on the rock.” She nudged his body and it shifted slightly; whether he’d heard her and complied, or had simply lost his hold along with his strength, he wasn’t sticking.
Roi tilted her carapace and managed to get all four claws on her right side beneath him. The edge of her body was too blunt simply to slide under him, so she tried to raise him with her claws first. She was not so old and weak that his weight should be immovable, and she was sure that once she got him on to her back she would be able to move quickly enough.
She strained against the rock. The very posture that she was forced to adopt undermined her strength, but if she couldn’t raise him she could at least make it easier for Zak to complete the action by his own efforts.
She kept pushing, clinging to the hope that in a few more heartbeats the balance of forces would shift, he would slide into place, and they would dash to safety together, but whether or not Zak was striving to assist her, between the two of them he was barely moving.
She’d made a joke to Ruz about a rope, but it was exactly what she needed. She looked up at the tracker that Zak had assembled, wondering if she could use it somehow to lever him up. Then she noticed a sudden brightening, an aura of true, strong light seeping around the rock in the distance.
Roi hesitated, trying to imagine some way in which she might yet save them both. If they both died here, then it would begin to look as if the void itself was fatal, and Ruz would not be so foolhardy as to try to make the measurements himself. The chances were that nobody would leave the Splinter again.
Zak twitched, then tapped one claw against her.
“Run, you fool!”
She bolted for the crack and skidded over the edge, losing her grip by accident but then understanding that it was better this way, better to fall. She bounced painfully against the jagged rock, but kept her claws tightly closed, refusing to slow herself. The rock around her was brightening, and she could feel the heat of the raw, unfiltered Incandescence growing above her.
She hit the floor, bruised and aching, but forced herself to limp down the tunnel away from the searing light. Ruz appeared beside her and she climbed on to his back. She clung to him tightly as he sprinted to the intersection and around the corner.
He kept running until it was clear that they were sheltered by the rock, immersed in nothing but ordinary brightness. Roi listened to the pounding of their hearts. Ruz sounded almost as shaken as she was.
After a while, she spoke. “He was too weak to move. I couldn’t shift him.”
Ruz said gently, “He might have died in the Null Chamber instead, but it would have been soon, whatever he did. This was the risk he chose.”
“I know.”
“He did a lot in one lifetime. More than any of us. What he learned, what he taught, what he changed.”
“That’s true.” Roi let the sadness sweep over her. In the end, there was only work, only the Splinter, only the next generation of hatchlings, and the next, on and on into the future. Nobody could live forever. But Zak had woken them all from a daze, woken them to a new kind of thought, a new kind of work, a new kind of happiness. Even if the Splinter itself had not been at stake, he deserved to be remembered for that.