Greg Egan - Incandescence

Roi drew a map for the light-makers showing the way to Bard's team, and the two groups parted. Ruz agreed to carry the light machine on his back; he took the rear harness so as not to obstruct Roi's view ahead.

They toiled on toward the junub edge, resting as they wished and using the machine to enable them to travel through the darkness. At first Roi found the strange, shallow illumination it cast disorienting, but after a dozen cycles she was accustomed to it, her mind switching easily between the two ways of seeing.

It was hard work winding the spring, though. "I want you to improve on the design," she told Ruz.

"In what way?"

"I want a version that works unattended, filling itself with light when there's light to spare, then releasing it in the darkness."

As they approached the edge the tunnels became increasingly strewn with rubble and the walls ever more fractured. Some of this might have been due to the Jolt, but Roi had heard descriptions of the area that long predated that event. It was easy to believe in a crack in the outer wall here, if not so easy to reach it.

Ruz, who had been timing the lengths of each stretch of light and darkness, reported that he'd finally started to detect a small asymmetry between successive times spent in the dark. Now that they were a significant distance away from the Null Line, when the Splinter moved junub of the Incandescence the darkness came earlier, and lasted longer, than when it moved shomal. Roi had already noticed a difference in the way the light penetrated the rocks, with the onset of brightness coming faster when it started from above than from below, but every sign that confirmed their guesses about the Splinter's motion through the Incandescence was important. Apart from anything else, they would be relying on the rock of the Splinter to protect Zak from any dangerous emanations; they did not want to misidentify the phases of the cycle and send him out in the wrong period of darkness, to find the Incandescence looming directly above him.

Shifting enough rubble to allow them to steer the cart through the tunnel became an impossible task. Roi helped Zak pack the instruments into his cavities, then had him climb on to her back. According to Zak's map they did not have far to go, but the map contained no annotations about the ease of travel along the tunnels it portrayed — let alone an up-to-date account that included the damage wrought by the Jolt.

Roi noticed a slight thickening in the sparse vegetation on the walls before she felt the faint hint of a wind, rising and dying with the light. This close to the Calm, that could only mean that the feeble wind had almost no rock to penetrate. She moved ahead cautiously, afraid that they might all be caught by surprise with no roof above them, but as they approached the intersection marked on the map as lying directly beneath the crack, the onset of light brought no blinding revelation. If anything, this place seemed less bright than the garm-sharq edge.

Still, the vegetation on the roof was the thickest Roi had seen since they'd set out from the Null Chamber. She set Zak down and clambered up the wall to explore it. She hadn't walked upside down in weight like this for a long time, and the encrusted surface didn't make it any easier.

She probed the surface gently with her claws. "The rock feels strong," she reported. "No gaps, no cracks."

Ruz said, "Maybe the vegetation's repaired it."

"All my maps are too old," Zak lamented. "We should have brought tools to cut our way out."

"Tools, and a very large work team," Roi suggested. She'd heard it said that the outer wall was at least a dozen spans thick, though like much common knowledge that claim might not have had much grounding in solid information.

Ruz said, "If there's a system of cracks, there might be other openings. Even if the vegetation got to all the old ones, the Jolt might have broken a way through somewhere else."

Roi climbed down to the floor. "Stay here with Zak," she said. "I'll take a look around."

She continued along the tunnel by which they'd reached the intersection. When the darkness came she froze and looked back, but there was no faint glow in the distance; she hadn't bothered to rewind the light machine, and apparently Ruz hadn't either.

As the light returned she advanced slowly, listening to the wind. The sound had an odd, resonant beat that she'd never heard before, and as she approached the next intersection it grew louder.

She turned right into the cross-tunnel, pursuing the sound. The floor of the tunnel was piled high with rubble, and it reached the point where it became easier just to climb on to the ceiling and stay there. When darkness fell once more it hardly seemed to matter; there might be cracks here, but at least she couldn't slip on a loose stone. She inched her way forward through the blackness.

When the wind rose up again, Roi could hardly believe that she was in the Calm. Even at the garm-sharq edge she'd felt nothing like this; her carapace tingled beneath the assault as if she was being pelted with fine sand.

The light now was brighter than she'd ever seen it. Brighter everywhere, but ahead, opposite the mouth of a side tunnel, a patch on the wall was almost blinding.

She dimmed her vision as much as she could, and approached the intersection cautiously. As she turned to peer into the side tunnel she saw the floor ahead awash with radiance, blazing too brightly to bear. She retreated, her heart racing.

When the next cycle of darkness came and the light ebbed from the surrounding rock, the intersection did not lose its strange radiance entirely. Roi approached the entrance to the side tunnel again, and looked toward the place that had been intolerably bright before. She could see a hole in the ceiling, with a ragged patch of the floor illuminated beneath it. The Incandescence was far away now, but it seemed that a part of its light was still reaching through that hole.

No doubt remained in Roi's mind: this was a crack in the Splinter's edge, leading out to whatever lay beyond. The next time darkness fell the Incandescence would lie safely on the other side, and the secrets of the void would be rendered visible to whoever dared step outside.

Rakesh was dreaming that he was a child on Shab-e-Noor, diving into a river with a group of friends, when Parantham appeared among them. She stood on the riverbank, smiling. "We've found an Ark," she said.

"Is this real, or am I dreaming?" he asked.

"Both," she replied.

His friends seemed troubled by the news. "Don't worry," he told them, "I'll be back as soon as I'm finished with this." A sense of panic was rising in his chest. Why couldn't he remember any of these children's names?

"If we let you come back," one said darkly.

Rakesh woke. He had not imagined the claim about the Ark; the telescope's report had entered his skull and the discovery had seeped into the dream's scenario.

He walked to the control room. Parantham said, "I was about to wake you."

"The news did that itself."

"What do you think?"

Rakesh scanned the data. The neutron star where the Ark had been found was twenty light years from the galactic center. Even with ninety per cent of the telescope's mirror in place the image of the find was just a tiny dark blur against the glow of the accretion disk. The spectrum was unmistakable, though; the object in question was made from the same material as the failed Ark that had been left behind.

This Ark would be immersed in powerful winds from the differences in orbital velocity across its length. In spite of the turmoil of its surroundings it had apparently managed to remain in place for fifty million years, kept from spiraling inward by a passive asymmetry in its structure that allowed it to gain energy from the wind if it ever sank too close to the neutron star. It was in precisely the environment for which it had been built. If its makers survived anywhere, surely it was here.