«Any other news?» she asked. «No word of new work teams?»
«New teams?» Zud sounded baffled.
Roi couldn't think of an easy way to characterize the notion of a team of which Zak might be a member. «Doing new jobs. Jobs you'd never heard of before.»
Without breaking his pace, Zud diverted three legs to a drumbeat of amusement. «Jobs I'd never heard of? Jobs someone made up from thin air?»
In the face of such mirth from a team-mate, Roi's habit was to retreat graciously into silence, but in her new role as a traveler she felt emboldened. «Do you think every job we do now always existed?»
«They're all necessary,» Sia said. «If there ever was a time when they weren't being done, it would have been disastrous.»
«They're all
useful
,» Roi countered. «But we might have done something different in the past, to meet the same needs. Or our needs might have been different.»
«Different
needs?»
Zud had a way of making her perfectly reasonable conjectures sound like oxymorons.
«Is your cargo the same for every trip?»
«Of course not,» Sia replied. «But it doesn't change so much that you could say our job has changed. And it all evens out in the long run.»
«What if there's a serious famine? Then my own job would certainly change: I'd have to keep people from storming the reservoir.»
Sia disagreed. «It's still the same basic function: keeping the food supply healthy and intact, whether it's saving it from mites, or from starving hordes.»
Roi was exasperated. «What if the ground fell? What if tunnels collapsed? What if the world was ripped in two? Would that be enough to change anything?»
Both her companions fell silent. Roi couldn't decide whether they were tacitly conceding the argument, or whether she'd offended them by speaking so forcefully. Perhaps she'd overstepped the mark.
After a while, Sia explained gently, as if to a child, «Life is hard, things aren't perfect. So we speak of living in a broken world. It doesn't mean that the Splinter was really part of something larger that was literally torn apart. That's just a story, Roi. The world has always been this way, and it always will be.»
Roi stayed with the couriers until they reached their depot, then she looked around for a place to rest. She was as tired as she'd ever been after a shift at the edge; even with nothing to carry, she had found it hard work keeping up with Zud and Sia, who were used to following a tight schedule and completing the ascent in a fixed time. The wind was already so much weaker than she was accustomed to that she felt no need to hunt for a sheltering lode; she simply slipped into the first empty crevice she found, and shut off her vision.
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.
As she approached the rendezvous point, Roi began to wonder how she might locate Zak, given that she'd be arriving a full shift earlier than he was expecting her. Despite having started the journey doubting the motives behind his invitation, she was eager to see him now, and she couldn't bear the thought of merely killing time while she waited.
When she passed through the intersection he'd nominated she was unsurprised to find it deserted. She traveled to the far end of the tunnel along which she'd approached, then doubled back and explored each of the cross branches. There was no one in sight.
She took out the last of the guide maps that Zak had given her. The invisible abstraction of the Null Line was clearly marked, and a chamber that it crossed was just a few dozen spans away. Roi knew that Zak wasn't here for his health; he'd admitted to her that his prolonged stay had actually weakened him. However, he claimed that the absence of weight simplified his search for its nature and origins, which sounded as paradoxical to Roi as striving to learn about the lives of susk by making sure that none of the creatures were around to distract you. Knowing Zak, merely being close to the line of weightlessness would not be enough for him. Whatever he was measuring, he would be measuring at the Null Line itself.
Roi headed for the chamber.
As she approached the entrance, her eyes caught a faint glint of metal, and she thought there might be a vein running along the far wall. After a few more steps, though, she realized that the perspective was wrong. A strand of metal, much thinner than any vein, ran through the middle of the chamber, far from any of the walls.
She reached the entrance and looked around. A fine web of the same material criss-crossed the chamber, supporting the central thread. Anchored at points in the web were various small, intricate devices; at this distance she couldn't hope to fathom their detailed construction, let alone their purpose.
Suddenly she noticed a figure moving across the far wall. Maybe Zak had been resting in a crevice, or perhaps she'd simply been slow to spot him in the chamber's uniform light.
Roi drummed out a greeting with all the legs she could spare without losing her grip. Zak didn't reply, and for a moment she thought he hadn't heard her. Then he sprung into the air and floated gracefully across the chamber toward her. As he approached, Roi saw that he'd given himself a slight spin, and it was soon apparent that this was not an accident but a carefully judged manoeuvre, because he landed nimbly beside her.
«Welcome to the Null Line,» he said. «How was your journey?»
«Safe and happy. I'm sorry I'm early.»
«Don't apologize! I'm glad to see you. We have a thousand things to discuss.»
Roi had never seen him so excited, and she wasn't prepared to flatter herself into thinking it was due solely to her arrival. She said, «You've found something, haven't you? Something simple?»
Zak hesitated. «Perhaps. I've discovered something interesting. But there's a problem as well.»
«What have you found?»
«I think I can explain the weights on the map,» he said. «I think I've made sense of the pattern.»
«How?» Roi was elated. She had suspected that he would succeed eventually, but she'd never imagined it would come so quickly.
«That will take some care to explain properly,» Zak said. «You'll have to be patient with me.»
«Of course. But.»
«How can there be a problem, if I've done what I say I've done?»
«Yes.»
Zak said, «It's beginning to look as if the map is wrong. I think I can explain the weights on the map, but I don't think the map matches up with reality.»