Incandescence (27 page)

When Rakesh had no one left to follow he backtracked along the tunnels, not waiting for his avatar to meet up with Parantham's before filling her in on what he'd seen.

"The same here," she replied. "Perhaps the Arkmakers were constrained by a need for activity cycles in the ancestral biology, so they put in some internal, or social, cue to take the place of the diurnal triggers that would have been present on the home world."

"Sleep, glorious sleep," Rakesh rhapsodised. "These truly are my cousins."

Their avatars returned to the fork where they'd parted. "So is everyone dormant now," Rakesh wondered, "or is this night someone's day?" He was about to suggest that they go hunting for signs of activity when he saw two creatures, identical to the farmers, approaching along the tunnel where Parantham had just been.

They were moving quite briskly, but pausing now and then to scrutinize the tunnel wall. Looking for pests, like the farmers in the chamber? Or hunting for some particular food?

The pair stopped completely, and Rakesh flew closer to see what they were doing. One was scraping fungus from the wall with its claws, while the other opened up the side of its body and removed a small, detached sac or bladder full of dark fluid. The contents were not literally opaque, but came as close to it as anything Rakesh had seen so far.

When the first creature had finished cleaning the wall, the other one punched a hole in the bladder with the tip of one claw, and began squeezing the fluid on to the wall in a slow, painstaking fashion. As Rakesh manoeuvred himself into a better vantage point, he saw that a complex pattern of intersecting lines was already present, marked on the wall with a thinner, paler version of the bladder's dark contents. Line by line, this Arkdweller was repainting a faded sign.

Parantham caught up with him, then hovered beside him, watching in silence. When the signwriters had finished the two travelers remained, gazing at the strange symbols.

Zak called out, "Just a few more spans, and I'm there!"

He sounded exhausted, but utterly determined to complete the arduous climb. Roi circled anxiously around the edge of the crack. When she'd helped him up to the entrance, he'd struggled to maintain his hold on the steep, jagged surface, and she had doubted that he would make it all the way through the outer wall. She had underestimated his reserves of strength. He hadn't taxed himself needlessly on the journey; he hadn't even forced himself to stay awake to make polite conversation with his bearers when he'd felt like resting instead. He had been saving everything for this moment, and now it seemed that his strategy was about to prove its worth.

The light machine stopped chugging but it was out of reach, so Roi left the darkness undisturbed. On Zak's instructions she and Ruz were clinging to the ceiling, the idea being that if whatever had killed those who'd ventured out before was present in the void as well as the Incandescence, they would be less exposed to it here than anywhere on the floor nearby. In fact, as Roi had helped Zak into the entrance, she had seen by the glow of the light machine that the crack was twisted in a way that allowed no direct line of sight. Still, during the shomal dark phase some light from the Incandescence had nonetheless made its way right down to the floor, so she couldn't fault Zak's logic.

Zak exclaimed suddenly, "I'm outside!" A moment later he added, "There's an arc of light. I don't understand this."

"An arc?" What did he mean? "Zak?"

There was a long silence, then he replied in a labored voice, "I need to take some measurements. I'll explain everything when I get back down."

"All right." Roi was desperate to hear exactly what he'd witnessed, but she knew it was unfair to expect a running commentary. Zak didn't have much time, and he needed to concentrate on setting up the instruments and collecting the crucial data.

Whatever else there might be to discover in the void, the one possibility in which they had invested the most hope — and planning — was that Zak would be able to locate a distant object that he could track for a while, in order to obtain an independent measurement of the Splinter's motion. From inside the Splinter, there were really only two distinct numbers that could be measured: the ratio of the garm-sard and shomal-junub weights, and the ratio between the periods of the shomal-junub cycle and the turning of the plane of the Rotator's spinning bar. Those numbers were in agreement with Zak's principle, but beyond that they revealed nothing about the geometry through which the Splinter was moving. If the simple geometry that the team had found in their calculations was the right one, then the time it took the Splinter to orbit the Hub would be identical to the period of the shomal-junub cycle. If all orbits at a given distance from the Hub were the same, regardless of their angle of inclination — the assumption of symmetry on which the simple geometry was based — then a stone moving shomal and junub of the Null Line would take the same time to complete its orbit as the Splinter itself, and so it would return to its greatest distance shomal of the Null Line after exactly one orbit for both.

How could you mark a fixed point on an orbit, though, in order to measure the time it took to return to it? The idea that two orbits at an angle to each other always intersected at the same two points was the very assumption they were trying to test, so it could not provide the signposts. The only method anyone on the team had been able to come up with was to rely on a different assumption — that objects far from the Hub moved on slower orbits — and then to hope that, with the Incandescence out of the way, it would be possible to observe something in the void so distant that it was as good as fixed. The apparent motion of that distant beacon would then be due — in the most part — to the Splinter's motion around the Hub.

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.

Ruz said, "Are you badly hurt?"

"No. Give me one shift and I'll have my strength back."

"You want to go back there?" Ruz's tone was neutral; he wasn't going to pressure her to take Zak's place, but nor would he try to dissuade her.

"I've walked beneath the void once, I can do it again. And I'm sure there's something out there that we can track, something we can measure." Roi pictured the strange ribbon of colors stretched across the darkness; she had no idea what it was, but she had seen lights moving within it.