Greg Egan: Incandescence

Upon waking, Roi's first thought was that she didn't understand the wind . In the garmside, it blew in from the Incandescence at the sharq edge and battered its way through the porous rock of the Splinter, finally escaping at the opposite edge. In the sardside, the flow was reversed. Between these opposing winds lay the Calm. The pattern of the wind was somehow related to the pattern of weights, but the nature of the connection was far from obvious: the wind certainly didn't blow the way things fell. The Null Line lay in the middle of the Calm, but the Calm extended far beyond it, encompassing a whole plane that stretched out in the shomal and junub directions, as well as the Null Line's rarb and sharq.

Roi roused herself and resolved to make an early start, all the sooner to discuss this problem with Zak.

Even here, her cycle seemed to be synchronized with many of the locals, but the workers heading for their shifts inspired no feelings of guilt in her. The softness of the light made everything seem slightly unreal, until she made a conscious effort to adjust her vision; she'd accommodated to the change as she'd traveled, but on waking she'd reverted out of habit to the minimal sensitivity more suited to the edge.

There was a pattern to the light too, of course. It seemed only reasonable that everything should be brightest where the wind from the Incandescence struck the Splinter with the greatest force, though she'd heard that the sard-rarb edge was not as bright as the garm-sharq. Was the wind there weaker, or was there another reason? Perhaps Zak would follow up his survey of weights with one of wind, and another of light.

As she continued her ascent, Roi pictured the levels of Zak's map embedded in the world around her, a succession of intangible layers to be crossed before her journey could end. She wasn't carrying a copy of that map, but from her memory of it she could imagine herself picking up pace, each step carrying her further than the last as the burden of weight gradually eased.

Near the end of the second shift, Roi came across a work team taking metal from a vein in the rock. The vein ran neatly along the wall of a chamber, although it was possible that this team, or their predecessors, had shaped the chamber expressly for the purpose of extraction.

The exposed vein made a striking sight. Metal shone with an eerie uniformity that made it unlike any other substance Roi knew: it was impossible to discern any structure within it, or even behind it. If people's carapaces had been made of metal, their inner organs would have been completely invisible, reducing their appearance to an inscrutable surface sheen.

The team was using an assortment of tools to prise the metal from one end of the vein. Roi could see a long, empty cavity extending away from the point where they were working, a roughly hemicylindrical indentation colored with vegetation that grew thicker with distance. There must have been a time when the whole formation had glistened with metal, and perhaps there'd be a time when the entire vein would be empty. People diligently scavenged the rare material, but that never seemed to be enough to fill the need.

There were people who insisted that these veins replenished themselves, by some process too slow for anyone to witness, rendering any shortage a temporary inconvenience. Roi was skeptical about that theory, but even more so about the supposed corollary. Plants were undeniably replenished by the wind, but if the wind carried metal into the Splinter not only was the process too slow to witness, it was too slow to be of any use.

If metal didn't grow from the rock like a weed, though, then there must have been a time when nobody had been extracting it. Regardless of the certainties Zud and Sia had expressed, there must have been a time when no one had heard of such a team.

How long could that time have lasted? There had to be some limit to how long the metal could have lain untouched in the rock before someone had realized how to make use of it. Perhaps a thousand generations, perhaps a million, but the era in which people had failed to use metal could not stretch back forever.

So, what had come before that? If metal couldn't grow, the vein itself must have always been there.

Which meant there must have been a time when there were no people at all.

Early in the third shift of her journey, Roi stopped near a fork in the tunnel and took a weight measurement. The navigation sign told her the lengths of the tunnel's three branches, and where they led. Her measurement told her that she was slightly more than halfway to the Null Line.

At first she thought this meant that she was roughly on schedule, but on reflection she realized that the news was far better: by Zak's count of levels crossed, she was well ahead. She reviewed the maps Zak had given her to guide her to their meeting place. She'd wandered away from his suggested route, but she wasn't far off course. She set off again with her energy redoubled.

Though her eyes were adapting to the ever softer light, they couldn't render the change imperceptible. Roi was used to the rock around her being noticeably brighter when she looked in the garm-sharq direction, with a characteristic drop in intensity as she turned away from that all-pervading beacon. Here, the distinction had become much subtler, and every contrast that depended on it was equally diminished. It was not that people or plants had ceased coloring and complicating the light, but many of the cues she had grown accustomed to were missing. When her team-mates working in the crops came to the edge of a field and changed direction, she could see patches of brightness temporarily imprinted on their carapaces, a record of their earlier orientation that took a few heartbeats to fade.

The vegetation was unmistakably sparser now, but so were the people. Roi could see none of the signs of a serious food shortage, such as unpalatable plants lying around half-eaten; desperate people would chew on anything, but most weeds tasted so bad that it was impossible to swallow them. She had to stay alert to spot enough food for herself, but that was only to be expected when she was moving through unfamiliar territory, away from the abundance she was used to.

As the shift wore on, the pleasant buoyancy she'd felt since the halfway mark began to mutate into something disconcerting. It was no longer just implausibly easy to ascend a steep tunnel; she noticed herself beginning to grip the floor by making her claws adhere slightly, in the same way she would grip the ceiling in order to walk upside-down. Sometimes her lightness even felt like the product of an upward force, the pull of an invisible assailant opposing her weight and attempting to dislodge her. When this happened she'd freeze on the spot, waiting for the bizarre tugging sensation to subside.

She was not yet in the Calm as cartographers defined it, but the air was still and silent to the limits of her senses. The tunnels were not quite barren or deserted, but the flatness of the light magnified the sense of solitude and rarefaction.

As Roi encountered strangers, usually in twos and threes, she greeted them and tried to guess their purpose. Few people stayed long in the Calm. Couriers and other travelers passed through by necessity, and the sick and injured sometimes spent time close to the Null Line in the hope that the conditions there would speed their recovery. The couriers crossing between the quarters were easy to identify, and she met one male limping along with a gash across his side, but many of the travelers remained difficult to categorize. No doubt some were briefly escaping their own work teams and had decided to experience the restorative powers of the region, or even just its novelty. In one small chamber she saw a trio of youths simply playing, clambering around on the ceiling and then releasing their hold and slowly drifting down.