She had planned to stay for less than a shift before returning to the Calm to meet up with Zak and Ruz, but she found herself lingering, waiting for her eggs to be ready to lay. Six had been fertilized, and when their cases finally hardened she found a snug crevice close to the chamber where Gul worked, and she packed the eggs carefully into the gap in the rock.
She was aware of how strange it was that she was arranging for these hatchlings to be educated by their father, rather than leaving it to chance. The job itself was the thing, and every member of every work team, not to mention every hatchling, was supposed to be interchangeable. Still, in these dangerous times everyone's children needed to learn what Gul could teach them. She would have counselled any stranger to do the same.
Although Roi was late returning to the Calm, when she arrived she found that the cart Zak had hoped to receive several shifts before had only just been delivered. That the metalworkers, couriers and depot operators had managed to fulfill Zak's strange request at all — while the food around them became ever more sparse, and the world of constant brightness they had known all their lives flickered in and out of existence — was testimony to the robustness of the work teams. Some people, Roi suspected, would not miss a shift even if the Splinter itself was torn apart.
The cart was big enough to hold Zak, the instruments Ruz had built for him, and a reasonable amount of provisions. Roi had already collected some food on her way back from visiting Gul, but she spent another shift foraging until she had as much as they could carry. Although the Calm supposedly became less barren as you moved away from the Null Line, and so in theory they'd be traveling into a more bountiful region, Roi had spent so long around the Null Chamber that she knew a dozen places where the seeds that drifted in tended to settle and grow. She would not have the same local knowledge once the journey was under way.
There were two harnesses for the cart, strung together one behind the other, so she and Ruz could share the load if they wished, but the cart would not be unbalanced if they chose to take turns pulling it instead.
The whole team of theorists came to bid them farewell; Tan addressed Zak on behalf of everyone. "We wish you a safe journey, and clear observations," he declared. "Our frames are ready for your numbers and templates. You built this team from nothing; perhaps you will return to us with the knowledge that will make our work complete." Zak replied simply with a murmur of thanks, but the send-off seemed to lift his spirits.
Roi took the harness first, leaving Ruz free to walk ahead of her, checking for hazards and clearing obstacles. The Jolt had left debris almost everywhere, and the less-traveled the tunnel the more chance there was that nobody had yet moved it aside.
Their journey would take them rarb and junub, uphill all the way, but it would be a while before their weight made much difference. Even in near weightlessness the cart was unwieldy, but by far the greatest irritation was the darkness. In her earlier trips between the hatchlings and the Null Chamber, traveling alone with no burden, Roi had found it impossible to make progress once the light fell away and her vision failed. The path ahead could be clear for dozens of spans and she could declare to herself that nothing terrible would befall her if she simply advanced at a leisurely pace through the darkness, but her body would still refuse to obey her after the first few halting steps. Attempting the same thing with Zak swaying on the cart behind her was inconceivable, even if Ruz had been in the harness to remove him as an unknown. The periods of enforced rest might have been welcome if not for the fact that they came so much more frequently than they were needed, making them more frustrating than recuperative.
"What
is
light?" Roi wondered, waiting for the darkness to end.
"A very fine part of the wind, perhaps," Zak suggested. "That would explain why it can penetrate more deeply through the rock than any other component. It seems it can penetrate anything but metal."
"It must be easily scattered, though," Ruz said, "or there'd be no light at all here in the Calm. The rock can't block it completely, but still manages to change its direction."
"Yes." Zak seemed intrigued by this observation, but unsure how to pursue it further.
Roi said, "If light is part of the wind, how can we hope to see anything at all once we're out of the Incandescence?"
"Some light might be scattered up to us from the Incandescence," Zak replied. "But the void itself might contain a faint wind."
"Including light?"
"Let's hope so," Zak said. "All we know for sure about the void is that it's a
thinning
of the Incandescence, to the point where nothing can reach us through the rock. That need not mean that there's absolutely nothing there."
The tunnel began to brighten again. It always took a while for the walls to begin glowing with their full intensity, though how much of that was due to the time it took for the light to penetrate the rock, and how much might be the product of a gradual transition between the void and the Incandescence, was hard to say. From outside the rock it might be possible to judge how sharp the border between the two regions was, though it would be risky to stay outside beyond the periods of full darkness.
It was only after they'd been traveling for nearly a shift and a half, according to Ruz's clock, that they decided to stop and sleep. Before the Jolt, most people had more or less agreed on the length of a shift, growing tired after a similar period of wakefulness. The stretches of darkness had led to an increase in that time, but not always an equal one for each person.
When they woke, Ruz was first in the harness. After a dozen light/dark cycles Roi took his place, and this time she finally felt the burden of pulling the cart uphill. The junub weight grew less than half as rapidly with distance as the garm and sard weights — and they were also traveling rarb, which contributed nothing — but beyond those excuses it was a measure of how slow their progress had been that it had taken so long to reach the point where they really cared which way was up.
The Calm appeared more sparsely populated than ever; apart from occasional couriers that Roi glimpsed in the distance, their role made obvious by carts of their own, the tunnels seemed deserted. The expeditioners passed the time with light-hearted speculation, eschewing any grim predictions about the fate of the Splinter. By the end of the journey's second shift, Roi and Ruz were dragging the cart together, with the lead harnessee also keeping a lookout for obstacles. It was hard work now, and Roi was beginning to feel that their enforced breaks didn't come a moment too soon.
Halfway through the third shift, as they slowed for the onset of darkness, Roi noticed a flicker of light ahead. At first she thought it was merely a lode in the rock that was dimming more slowly than its surroundings, but as the darkness deepened the contrast only grew stronger. A reddish patch of light stood out against the blackness; it was an unsteady glow, but it never failed entirely. It was moving slightly, with a rhythm that reminded her of a person's gait, as if someone was carrying the source of the light toward them.
Ruz said, "Can you hear footsteps?"
Roi listened carefully. "Yes."
"There are five people," Ruz declared. "And some kind of machine."
"I'll take your word for it." A dozen heartbeats later, she could make out two people in the front of a small group. The light was coming from an object strapped to one of their backs.
Zak said quietly, "That I lived to see such wonders."
Roi called out a greeting, unsure if the three of them would be visible by this strange illumination. A reply came back, cautious but friendly.
When the group drew closer, Roi could see that Ruz was correct: there were five people. They made introductions; the light-bearer was called Lud, and the others were Jos, Rud, Cot and Sad.
The light that emerged from the machine on Lud's back was weak, rendering the group sketchily. Their bodies were merely hinted at by a glimmer of surfaces, as if their carapaces had turned to metal. Seeing your companions' beating hearts was not the point, though; this modest light would still be enough to allow you to spot obstacles and walk through the darkness with confidence.
"Where are you headed?" Ruz asked politely. Roi was sure that he was twice as eager as she was to hear how the light machine worked, but it would be discourteous to raise the matter immediately.
"We have no destination yet," Jos replied. "We want to know what's happening to the Splinter, so we've left our teams to search for answers."
Roi could hardly believe what she was hearing. They'd left their teams?
How?
Had the Jolt shaken them free, like the rubble it had torn from the solid walls?
She said, "We have some ideas about what's happening to the Splinter. We believe something has pushed it, and now it's falling back and forth, in and out of the Incandescence."
Lud said, "Falling back and forth?"
"If you throw something shomal from the Null Line," Ruz explained, "it will reach a certain distance, fall back to the Null Line, go past it some way junub, fall back again, and so on. We think the Incandescence ends if you go far enough shomal or junub, and that's why the light comes and goes."
The group talked this over among themselves, then asked to hear more. Zak remained quiet, which usually meant that he was tired or in pain, so Roi explained his idea of the Splinter orbiting the Hub, and the experiments in the Null Chamber that seemed to support it.
While they were talking the light from the machine faded, and its whirring sound died away. But the walls were already beginning to brighten, and soon Roi had a normal view of everyone. They had a small cart with them, full of metal parts.
Cot climbed on to Lud's back and began turning a handle attached to the machine. Ruz could no longer contain himself. "It's spring driven, isn't it?"
"Of course," Lud said. "Trying to crank it smoothly and walking at the same time would be impossible."
"
But what makes the light?
" Ruz's tone was drenched with such longing that he might have been a starving child begging for food.
Lud chirped with amusement. "Just two rough surfaces scraped over each other, under pressure. Rough enough to make a disturbance, but not so rough that they'll stick."
Jos added, "I found the effect completely by luck. I was grinding plants into a powder between two stones, and I grew tired of stopping work every time it grew dark. When I ground stone against stone with nothing between them, a faint light seemed to come from the point of contact. At first I thought I was just going mad from the darkness, but the more effort I applied, and the less of the mush there was to smooth the stones, the stronger the light became."
Roi said, "So you've left your old teams now? You've formed a new one, and you're looking for recruits?"
"Not exactly," Cot replied, working briskly to ensure that the spring was fully wound before the darkness returned. "We still don't know what's the best thing to do. We'll form a team if that's necessary, but we're willing to join an existing one if they can make a good case that they know what's going on and that they're doing something useful about it."
Every time Roi thought she could no longer be shocked, these people outdid themselves. It had taken a great struggle for her to tear herself free of her work team to join Zak. On that first journey to the Null Chamber she had never been able to admit her intentions, even to herself. Now here were five people roaming the Splinter, challenging every passing stranger to make a
reasoned bid
for their labor, as if the whole idea of recruitment had been turned inside out.
Zak spoke softly. "Some people are trying to build a tunnel that will change the way the wind pushes on the Splinter. If they succeed, they hope it will carry us to safety. I'm sure they could use your skills."
Lud said, "I can make no promises, but we'd be happy to talk to them, to hear their case."
Ruz said, "We can draw you a map, give you directions."
"You're not going there yourself?" asked Sad.
"We have another task." Roi explained about the crack in the wall, and the observations that they hoped would clarify both the Splinter's ordinary motion and the nature of the Jolt.
The idea struck a chord with the light-makers, and they seemed torn between joining Zak's expedition and heading for the sardside and the tunnel-makers. Zak, however, explained that he would be making the observations alone and that his two assistants were all that he needed.
Cot said, "Then at least take this with you to help you on your way." He opened the cart and produced a second light machine. "We brought two spares, and plenty of parts. If you take this one, we will still have no trouble reaching the sardside."
Zak said, "Thank you." Roi would have preferred an extra body or two to help pull Zak's cart; this was more weight to carry, and now they'd have no excuse to rest when darkness came. Still, at least this way they could choose their own pace.
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."