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.”