Incandescence

by Greg Egan

  The other part of her recoiled from that memory. She still reveled in the joys of belonging to a team, but the work she had chosen was utterly different. Instead of being blissfully content with the same healthy crop at the end of each shift, she could only claim success now from something new: a revelation, a contradiction, a twist that turned their old guesses inside out. If they ever did reach the end of the mysteries of weight and motion — and if Zak's legacy finally granted his people the power to steer their fate — she would welcome the return of ease and safety like everyone else, but she did not know how that second part of her would go on living.

  Ruz was younger and far more rested than she was, so Roi let him climb ahead of her. She heard his exclamation of delight when he emerged on to the surface. By the time she joined him, he was already beside the tracker.

  "Let me get oriented," he said. "This way is rarb, around the Splinter's orbit." He swung the tube of the tracker toward the center of the arc. "And this way is garm, toward the Hub." He turned it to the left, away from the arc. "So the garmside of the void appears completely black, while on the sardside this arc of light is wrapped around the rarb direction." He had heard the same basic facts from Roi, but finally seeing the void's peculiar geometry for himself seemed to compel him anew to seek an explanation. "A quarter of a circle. Why a quarter? The Splinter beneath us is blocking half the view, but why should we be seeing light in only half of what remains?" He hesitated, then answered his own question. "The missing half is in the direction of the Hub. So the Hub must be responsible."

  Roi said, "Do you seriously believe that we're almost as close to the Hub as we are to the Splinter — to the rock beneath our claws?" That was a terrifying prospect. She had always imagined the Hub as something small and distant, not a looming presence they were on the verge of swiping, like some careless runner scraping against a tunnel wall.

  "Maybe not the Hub itself," Ruz replied. "But suppose we're close to the point where orbits become unstable. Imagine that region as a huge ball around the Hub. There's nothing solid in it, but presumably light can't cut across it to reach us, because it spirals in and hits the Hub instead. There's no rock, no metal, beside us the way the Splinter is beneath us, but the geometry still blocks the view."

  "That does make sense," Roi admitted. She tried to picture the paths that the light might take as it flowed in from the distant reaches of the void. "The light's not moving in circular orbits, though, so where it gets caught by the Hub might not correspond to the point of instability for the Splinter. I wish I knew exactly where rarb and garm lay from here; if we measured the angle from rarb to the start of the arc, that might tell us something."

  "Tan can probably think of a way to do that; the signage teams make trickier calculations all the time." Ruz surveyed the arc. "And that's the bright light you mentioned? To the far right, just above the Splinter?"

  "Yes."

  "We need to get some new recruits here," he suggested, "making measurements constantly, shift after shift. Between the orbit of this Wanderer, and the paths of the light through the void, there must be enough information to pin down the geometry exactly."

  "Let's hope so." Roi wasn't sure how complicated the geometry might yet turn out to be. Now that they knew that it lacked the perfect symmetry they'd hoped for, in principle it could be as messy and irregular as the walls of a tunnel.

  Ruz timed the Wanderer as it moved across the width of the arc. Roi looked out into the void, freed of the tracker's narrow view, wondering what these lights might be. Small pieces of the Incandescence, severed from it somehow? She didn't understand why the Incandescence was confined to a plane at all, but perhaps there was some way that parts of it could break free, over time.

  Or perhaps it was the other way around. Perhaps these points of light began by moving freely, their orbits aligned in all manner of directions, and over time the geometry around the Hub gathered them together and dragged them down into the plane. If that was the case, then these lights were not the offspring of the Incandescence, but its source, its replenishment.

  Roi felt giddy, but she could almost picture it: a void full of lights that spiraled in toward the Hub, which swept them together into a plane of wind and radiance. That was the world the Splinter had been immersed in before the Jolt, and from within it had seemed boundless and unchanging. Gradually though, even particles of wind would drift close enough to the Hub to fall, irretrievably. So there would need to be more of the lights coming in, endlessly feeding the Incandescence.

  She was tempted to share her ideas with Ruz, but that could keep until they were inside again; better to let him concentrate on his measurements. As she watched the lights drifting across the arc, the Wanderer suddenly grew brighter. A luminous spike transected it, and a second point of brilliance blossomed at the tip of that spike and moved away.

  Ruz said, "Did you see—?"

  "Yes."

  "What was that?"

  The smaller bright point had vanished; Roi wasn't sure if it had traveled beyond the band of visibility or simply become lost in the crowd, but she couldn't see anything moving.

  "The weight must have torn a piece off it," Roi said. "Like the Splinter dividing."

  "It's still there," Ruz said. "As bright as ever."

  "It's not rock," she said, "it won't break up the same way. Rock by itself is dark; this is wind and light, it's all the things that become the Incandescence."

  "What strength does wind and light possess, to hold together at all?" Ruz protested.

  "I have no idea," Roi said. "There's still too much we don't know."

  The dark phase was almost over; they made their way to the crack and began the descent.

  They agreed that it was time to return to the Null Line, to tell the rest of the team the sad news about Zak, and to start working together to make sense of their observations. They put the light machine inside Zak's cart, and took turns in the harness.

  The downhill journey was easy, and with the light machine to keep them going they made good progress. As they trudged through the tunnels in the shallow light, Roi found herself wondering if her eggs had hatched, if her children were already taking lessons from Gul. Let there be another Zak or two among them, she thought. The Splinter was going to need them.

  Suddenly the tunnel was drenched in brightness. Roi tensed, gripping the floor, prepared for another Jolt. Ruz was behind her, dragging the cart; she heard him take a few unwilling steps from sheer momentum before he froze too.

  The light peaked, then faded. After a few heartbeats there was darkness; the light machine was still grinding away, but Roi's eyes were too dazzled to register its effect. There'd been no Jolt, no change in weight.

  Ruz spoke first. "What we saw break free from the Wanderer. "

  "Just passed us by," Roi said. "The Jolt must have been the same kind of thing, only a bigger piece, or a more direct encounter." She was certain now that her guess about the lights was correct: they fed the Incandescence, and it was not a gentle process. "The geometry is tearing the Wanderer apart, and some of the splinters from it will fall toward the Hub. We're so close to the Hub that it's inevitable that we'll be in the way of some of them."

  The light machine fell silent.

  "Then which way does safety lie?" Ruz asked. "We need to move away from the Hub, or the next Jolt could push us past the point of no return. But if Bard's tunnel is ever completed, and we succeed in making the Splinter spiral outward, how can we be sure that we won't collide with the Wanderer itself?"

  Roi said, "We can't be sure of anything. All we can do is what Zak taught us to do: measure, calculate, try to understand."

  Ruz shifted nervously in the darkness. "How many generations will it take us to understand enough to climb out of this trap, without killing ourselves in the process?"

  "Maybe one," Roi said hopefully, thinking again of her own children. If they grew up juggling templates and calculating the geometry of the void, it might not be the same struggle fo
r them as it had been for their elders.

  Ruz said, "We might not have that much time."

  17

  Rakesh said, "There's no question that they're sentient. And there's no question that the bulge is a dangerous place. The question is, would they understand what it is we have to offer them?"

  Parantham gazed back at him across the control room. "Probably not. Not straight away. Perhaps we could work up to it over time."

  "How much time do we have?"

  "This Ark's not in any kind of imminent danger."

  Rakesh said, "We can't do much for them if we're exiles here ourselves."

  "You mean Csi's story? You're afraid the Amalgam won't take us back if we don't get out before the news about Lahl spreads around the inner disk?"

  "Do you think I'm being paranoid?"

  "I don't know." Parantham thought it over. "The Amalgam has a strong tradition of hospitality, but it also has a strong tradition of cutting off those who abuse it. I think it will come down to whether or not people will believe that Lahl was an act of bad faith by the Aloof, or just a genuine traveler who covered her tracks."

  "Or in the absence of conclusive evidence either way," Rakesh suggested, "it will come down to where they want to place the benefit of the doubt, how they want to weigh the risks."

  "What risks? The Aloof have no more power to harm us by posing as citizens of the Amalgam than they have skulking down in the bulge."

  "Maybe, but they shouldn't have lied to us. That's the part that's hard to forgive. That's the part that makes it hard to trust them."

  "Maybe they had to lie." Parantham spread her arms. "Is this my body? Was I born with it? Am I lying to you by pretending to inhabit it the way you inhabit yours?"

  "If they were capable of pretending to be Lahl, surely they were capable of saying, 'By the way, we're not quite who we seem to be.'"

  "Just because we can imagine Lahl saying that doesn't mean they were capable of doing it — or capable of understanding why we wish they had."

  Rakesh put his head in his hands. "Forget the Aloof. What are we going to do about the Arkdwellers?"

  Parantham said, "Keep studying them until things become clearer. If you'd let me run some simulations—"

  "They're sentient, they have a right to privacy. We can't do anything like that without informed consent."

  "But we can spy on them as much as we like?"

  "There's a difference," Rakesh protested heatedly, "between sending avatars in discreetly to observe their public behavior and stealing DNA samples in order to run simulations."

  "Public behavior, as distinct from what? They don't seek privacy from each other for anything they do."

  "It's about consent, it's not about social taboos."

  Parantham raised her hands in a gesture of resignation. "You're their cousin, you're the child of DNA. You decide, I'll just keep my mouth shut."

  Rakesh knew he was being inconsistent, but he had to defend the compromise he'd struck. If they had ruled out clandestine observations, then there was simply no point being here; making their presence known to the Arkdwellers without studying them first would have been ineffectual at best, and at worst disastrous. But he would not countenance sequencing them without their permission; that would be treating them like animals.

  The Arkdwellers had language, spoken and written. They had tools, they had agriculture, they had industries. They had specialization: each one of them performed a particular role to keep the Ark running smoothly. Rakesh had at first suspected that these roles were innate biological castes, but that had turned out not to be the case. Rather, workers were inducted into teams by a kind of socially mediated bonding mechanism, which was powerful but not irreversible; they could be press-ganged into another team, if the right circumstances arose.

  Similarly, their agricultural and technological practices seemed to be culturally transmitted rather than genetically hardwired. The cultural legacy included a small amount of written material along with the predominant mix of oral instruction and learning by imitation, but did not contain anything that Rakesh recognized as history, or natural science. They did not seem to know about the Arkmakers, or to have any comprehension of what lay outside the Ark.

  How could he invite them into the Amalgam, when they had never even seen the nearest stars? How could he offer them sanctuary, when they had no idea how close to extinction their ancestors had come? They were not in any immediate danger; even in this crowded, chaotic place, it was possible to predict that nothing would tear them from their orbit in the next few millennia, and given how long they'd survived already they might remain unscathed for millions of years.

  In the long run, though, they couldn't rely on the Ark's design to protect them from all the perils of the bulge. Should they be left to live in peace, then, isolated and ignorant, until the inevitable finally happened and they were incinerated in a supernova or ferried by some new Interloper all the way to the singularity at the heart of Goudal-e-Markaz?

  Rakesh had made a promise to Lahl, and whether she'd been a citizen of the Amalgam or some kind of construct sent out by the Aloof was beside the point; what he had accepted was an obligation to take the responsibilities of any discovery seriously, and not treat these creatures as a mere trophy, a curiosity to be catalogued and then abandoned.

  He turned to Parantham. "I think we should leave before we risk getting stranded, but we should try to make contact with the Arkdwellers first. There's a chance we'll be able to come back eventually, but we have an opportunity now to plant some information that might help protect them, even if we can't return."

  Parantham considered this. "Contact can be disruptive."

  "So can being blind-sided by a neutron star that you never even dreamed existed."

  "We could go out," she suggested, "come to some arrangement with the eavesdroppers in the inner disk to normalise our status, then return to do this at our leisure."

  Rakesh said, "And will we come to some arrangement with the Aloof whereby they promise to let us in again? Or just take our chances and hope this wasn't a once-in-a-million-year opportunity?"

  Parantham wasn't happy. "If you're resolved to do this, I can't stop you, but I'm not going to participate."

  "I see." Rakesh was surprised by the strength of her disapproval. He hesitated, weighing up the options again.

  Every choice was risky; there was no perfect solution. But he would not leave the bulge until he'd done his best to help the Arkdwellers understand their history, and regain control of their fate.

  There were no cracks in the Ark large enough to admit his new avatar, so Rakesh took it through in pieces and assembled it in the tunnel. It was the size and shape of a typical adult Arkdweller, with the six legs of a male, but none of the Ark's inhabitants would mistake it for one of their own. The imperfect imitation was intentional; he wanted to communicate with the Arkdwellers effectively, not deceive them about his nature. He wanted his strange body to act as evidence, to back up his extraordinary claims.

  He and Parantham had gathered enough data on the Arkdwellers' leg-drumming to assemble a comprehensive picture of the language, and Rakesh had tweaked his mind not only to enable him to speak and understand it, but also to acquire new vocabulary, and grasp any other nuances or novelties that had eluded their survey so far. When he switched his senses into the new avatar, he drummed a few phrases softly, accustoming himself to the mode.

  "Wish me luck," he said, in his native tongue with his real mouth, addressing Parantham across the control room. She didn't reply, but Rakesh knew she would be watching everything. He would be glad to have her looking over his shoulder; even though she wouldn't actively participate, he hoped he could rely on her to warn him if she thought he was pushing the Arkdwellers too hard. Sharing a replicator with these people gave him no special insight into their nature, and he'd welcome a second opinion any time she cared to offer one.

  He set off down the tunnel.

  As he approached the farme
rs' chamber he slowed, and strained his hearing. The last time he'd been here the vibrations reaching his avatar had sounded like meaningless noise; now the hubbub was imbued with the unmistakable cadences of speech, even though he could not make out any individual words.

  He reached the entrance to the chamber and stood in plain sight of the whole work team, waiting expectantly for a shocked silence to descend, or a commotion to arise. He was sure that if an ambulatory scarecrow had approached the edge of a field full of farmhands on Earth, in the days before machinery, there would have been a dramatic response.

  The farmers ignored him. It was hard to judge their lines of sight, but Rakesh knew he was clearly visible in principle, and he believed that at least a dozen of the workers had looked his way and then continued tending the crops.

  This was, he decided, an encouraging sign: the mere sight of him wasn't going to spark a riot. If the Arkdwellers' lack of curiosity was alien to him, their lack of volatility could only make it less likely that Parantham's fears would turn out to be well-founded.

  He clambered down the sloping wall of the chamber, into the thick of the crops, and approached one of the workers.

  "To your life and strength," he drummed.

  "And yours," the worker replied, continuing past him.

  Rakesh turned and followed her. "Wait, please."

  "I'm busy."

  "Can't we talk while you work?" The farmers talked among themselves all the time.

  "I'm busy," she repeated. To the extent that Rakesh understood her tone, it was not unusually cold or hostile, merely emphatic. He wondered what, exactly, she thought he was. Some kind of grossly deformed member of her own species? He did not belong to her current team, of course, and that was the most important distinction.

  Another of the farmers was heading his way. Rakesh greeted him, and he received the same standard reply.