The Clockwork Rocket

decelerate-and-reverse phase, halfway through the journey. Relying on the status quo would not be an option.

Yalda led the group to a stairwell at the rim of the chamber, and they gazed up into its moss-lit heights. Four taut rope ladders ran down the center—installed early in the construction phase and retained in anticipation of weightlessness—but for now a more convenient mode of ascent involved the helical groove three strides deep that had been carved into the wall, its bottom surface tiered to form a spiral staircase.

“We’ll be climbing up four saunters here,” Yalda warned the group, “so please, take it carefully, and rest whenever you need to.”

Fatima said, “I don’t feel weak, but I’m getting hungry.”

“We’ll have lunch soon,” Yalda promised. Fatima was a solo, barely nine years old; Yalda felt anxious every time she looked at the girl. What kind of father would have let her travel alone across the wilderness, to enlist in a one-way trip into the void? But perhaps she’d lied to him in order to come here; perhaps he thought she was hunting for a co-stead in Zeugma.

The group was evenly split between couples and singles; the singles were all women, except for Nino. Yalda hadn’t interrogated Nino about his background, but she’d formed a hunch that he was that rare and shameful thing, a male runaway.

They began trudging slowly up the stairs; the pitch appeared to have been set to discourage running, should anyone have felt tempted. Their footsteps, and the whispered jokes of Assunta and Assunto up ahead, came back at them in multiple echoes from the underside of the stairs above. Beyond their own presence, Yalda could hear an assortment of odd percussive sounds, creaks and murmurs drifting down from higher levels. The workforce inside the mountain had fallen far below its peak, but it still numbered about a dozen gross, and most of the activity now was in the habitation high above the engines.

“Will the travelers be able to see the stars?” Fatima asked Yalda, trailing her by a couple of steps.

“Of course!” Yalda assured her, trying to dispel any notion that the Peerless would end up feeling like a flying dungeon. “There are observation chambers, with clearstone windows—and it will even be possible to go outside for short periods.”

“To stand in the void?” Fatima sounded skeptical, as if this were as fanciful as walking on the sun.

Yalda said, “I’ve been in a hypobaric chamber, as close to zero pressure as the pumps could produce. It feels a bit… tingly, but it’s not painful, and it’s not harmful if you don’t do it for too long.”

“Hmm.” Fatima was begrudgingly impressed. “And in the sky—will they be our stars, or the other stars?”

“That depends on the stage of the journey. Sometimes both will be visible. But I’ll talk about that with everyone later.” A moss-lit staircase wasn’t the place to start displaying four-space diagrams.

They emerged from the stairwell into a wide horizontal tunnel; this one ran all the way around the mountain, but the nearest junction was just a short walk ahead. Yalda offered no warning as to what lay around the corner; the light gave some clues, but the thing itself always took the uninitiated by surprise.

The chamber was no wider than the one below, but it was six times taller—and the broad stone columns supporting the arched ceiling were all but lost among the trees. High above their heads, but far below the treetops, giant violet flowers draped across a network of vines formed a fragmented canopy that divided the forest vertically. With no sunlight to guide their activity, these flowers had organized themselves into two populations with staggered diurnal rhythms, one group opening while the others were closed. Through the gaps left by the sagging, dormant blossoms, shafts of muted violet reflected back by the stone above revealed swirling dust and swooping insect throngs. Even the air moved differently here, driven by complex temperature gradients arising within the vegetation.

Yalda strode forward through the bushes that had been planted around the chamber’s edge, where the ceiling was too low for trees. “This might look like a strange indulgence,” she admitted. “When we have farms, plantations and medicinal gardens, what need is there for wilderness? But if our survival depends on the handful of plants we’ve learned to harvest routinely, this place still encodes more knowledge about light and chemistry than all the books ever written. Every living organism has solved problems concerning the stability of matter and the manipulation of energy that we’re only just beginning to grasp. So I believe it’s prudent to bring as many different kinds of plant and animal life with us as we can.”

“What kind of animals?” Leonia asked; she didn’t sound too happy about the prospect of sharing the Peerless with a teeming menagerie.

“In here right now, there are insects, lizards, voles and shrews. Soon we’ll be adding a few arborines.” Yalda watched the group’s reaction with her rear gaze; eventually it was Ernesto who said, “Aren’t arborines dangerous?”

“Only when threatened,” Yalda declared confidently. “Most of the stories about them are exaggerated. In any case, they’re our closest cousins; if there are medical treatments we need to test, there’s only so much you can learn from a vole.” It was Daria who’d sold her on most of these assertions—the same Daria who’d made half her wealth from impresarios’ claims about the creature’s ferocity.

Fatima said, “What happens when there’s no gravity? Won’t everything… come loose?”

Yalda squatted down and cleared a small patch of soil, exposing the layer of netting that sat over it. “This is attached to the rock with spurs at regular intervals. The root systems bind the soil together, too—and the soil itself is actually quite sticky. A handful of soil will trickle through your fingers easily enough, but an absence of gravity is not the same as turning everything upside down. What I’m expecting is that the air here and in the farms will grow hazy with dust, but there’ll be an equilibrium where that dust is re-adhering to the bulk of the soil as often as it’s breaking free.”

They took the stairs up to one of the farms, and ate a lunch prepared from the local crops. Wheat adapted well to sunlessness; it grew faster in here than on the farms outside, now that Gemma had all but banished night again. The disruption caused by the second sun varied with the season and the year—and there were periods when it rose and set close to the original, almost restoring normality—but the last Yalda had heard from Lucio was that he and her cousins had given up trying to adjust to the complicated cycle and were simply building canopies over all their fields.

Then it was on to the storerooms, workshops and factories, the school, the meeting hall, the apartments. They ended the day in an observation chamber close to the peak, where they watched the sun setting over the plain below, revealing the mountain’s stark shadow in the rival light from the east.

There was a food hall beside the chamber. Yalda found a free patch of floor among the crowd of construction workers and sat everyone down. Up here they were far enough from the sunstone to use lamps; it might have been any busy establishment in Zeugma or Red Towers.

Yalda dropped her recruiting spiel and let the group eat, with no accompaniment but the sputter of firestone and the chatter of their fellow diners. By now they’d seen not the whole of the Peerless, but at least one example of everything it contained. They’d reached the point of being able to imagine what it would be like to spend their lives inside this mountain.

Leonia, who’d been tense throughout the tour, now appeared almost tranquil; Yalda’s guess was that she’d made up her mind to find an easier way of avoiding her co than fleeing into the void in the company of wild animals. Nino looked haunted, but equally resolved to make the opposite choice. Looking back, Yalda realized that every question he’d asked her had concerned something innocuous or trivial; it was as if he’d wanted to appear engaged as a matter of courtesy, but he’d been so committed to his plan from the start that he’d preferred not to delve into anything that might risk swaying him.

With the others, she was unsure. It was as easy to undersell the problems the travelers would face as to oversell them. Anyone who reached the end of the tour believing that the project was hopelessly ill-conceived would walk away—but equally, anyone who was convinced that the triumphant return of the Peerless was inevitable would have scant motivation to join the crew. Rather than sentencing your descendants to indefinite exile, why not choose the version of events that lasted a mere four years, in which your death far from home was replaced by the imminent arrival of the most powerful allies you could hope for? Of course a Hurtler might incinerate the world before then, but it had been five years since Gemma’s ignition, so it wasn’t hard to imagine the same luck holding out for another five.

In between those two extremes was a sweet spot, where the mission’s potential was beyond doubt but its success remained far from guaranteed—allowing a wavering recruit to imagine their own contribution tipping the balance. Yalda aimed squarely for that result, and she no longer felt guilty or manipulative for doing so. The truth