The Clockwork Rocket by Greg Egan
Fatima said, “How do you know those are images of orthogonal stars, not ordinary ones?”
Benedetta gestured at her chest. “Look at the angle between the light and the histories of the ordinary stars. To them, the light’s traveling backward in time! Only the orthogonal stars could have emitted it.”
Yalda added, “And if the orthogonal stars’ future had pointed the other way, then the probe could only have imaged them once it had reversed and was coming back toward us. So we know the direction of the arrow now—not from the Hurtlers themselves, but from the light of these stars whose origin the Hurtlers share.” This finally put to rest Benedetta’s old fear: that the Peerless might be headed straight toward the orthogonal cluster’s past, requiring the rocket to function while opposing the entropic arrow of its surroundings. Now it was clear that it would not face that challenge until the return leg of the journey.
“And how far away are they?” Fatima asked. “These orthogonal stars?”
Benedetta looked down at the images. “We can’t be sure, because we don’t know how bright they are. But if they’re about as luminous as our own stars, the nearest could be no more than a dozen years away.”
The group absorbed this revelation in silence. Five Hurtlers were spreading lazily across the morning sky, and while Gemma itself was below the horizon, here was a promise of interlopers vastly larger than the baubles that had set that world on fire.
Just when Yalda was beginning to think that the stark new threat might push some of the waverers into making a commitment, Leonia broke the mood. “Six dozen probes went up,” she said, “and this is the only one that’s been recovered? What happened? Did all the others end up as craters in the ground?”
“That’s possible,” Benedetta conceded. “Landings are difficult to automate. But the real problem was returning the probes to this tiny speck of rock from such a distance. The world is a very small target; the tolerances required for attitude and thrust control were close to the limits of what any of us believed was feasible. We were lucky to get even one back.”
“But the Peerless will be traveling much farther,” Serafina noted anxiously.
“With people inside it to navigate,” Yalda replied. “It won’t be down to clockwork to get them home.”
Leonia was unswayed. “Be that as it may, when you rehearsed your great project—on a much smaller scale—you only had one success in six dozen. And you were hoping to impress us by juggling voles!”
The demonstration launch Yalda had arranged would carry six of the animals above the atmosphere, then bring them back down again—hopefully still alive. While clearly no surrogate for the flight of the Peerless, this was not a trivial achievement—and some people did find it reassuring to see that Eusebio’s rockets no longer exploded on launch, or cooked their passengers with the engine’s heat.
“What would persuade you, then?” Yalda demanded irritably. “A full-scale rehearsal, where we send up Mount Magnificent with a crew of arborines?”
Leonia responded to this sarcastically grandiose proposal with a much more modest alternative. “It might mean something if you went up yourself, instead of the voles.”
Before Yalda could reply, Benedetta said, “I’ll do it.”
Fatima emitted an anxious hum. “Are you serious?”
Benedetta turned to her. “Absolutely! Just give me a few days to check the rocket and re-arrange things for the new weight.”
Yalda said, “We need to discuss this—”
“That would be a lot more convincing than voles!” Assunto enthused. His co agreed. “What can an animal the size of my hand tell us about the risks of flight?” she complained. “Our bodies are completely different.”
Yalda looked on helplessly as the group debated Benedetta’s offer; the majority soon reached the view that nothing less would be of interest to them. Only Fatima was reluctant to witness such a risky stunt, while Nino struggled to summon up the appearance of caring one way or the other.
Yalda wasn’t going to argue this out with Benedetta in front of everyone; she sent the recruits off to kill some time at the Basetown markets.
Benedetta was already contrite. “That was poorly judged,” she admitted. “I shouldn’t have sprung it on you out of nowhere.”
Yalda said, “Forget about the timing.” Being made to look foolish in front of the recruits was the least of it. “Why do you think you need to do this at all?”
“We’ve talked about it for years,” Benedetta replied. “You, Eusebio, Amando… everyone agrees it would be a good idea to send someone up—but always later. How long is it until the Peerless is launched now?”
“Less than a year, I hope.”
“And we still haven’t put a single person on a rocket!”
“Flesh is flesh,” Yalda said firmly. “What are voles made of—stone? When it comes to the Peerless, the things we have to worry about will be attitude control and cooling—and we’ve got both of them down to a fine art: in the last four dozen test launches, they’ve worked flawlessly. It’s only the landings that have failed.”
“And only three times,” Benedetta pointed out. “So those aren’t bad odds that I’d be facing.”
Yalda said, “No… but if you did this, what would it actually tell us? Whether you survived or not, how would it make the Peerless safer?”
Benedetta had no ready reply for that. “I can’t point to any one thing,” she said finally. “But it still feels wrong to me to try to launch a whole town’s worth of people into the void, without at least one of us going there first. Even if it’s only a gesture, it’s a gesture that will calm some people’s fears, win us a few more recruits and quieten some of our enemies.”
Yalda searched her face. “Why now, though? You see an image of the future—proof that it’s fixed—and suddenly you’re offering to surrender your life to fate?”
Benedetta buzzed, amused by the implication. She held up the paper from the probe. “If I stare at this long enough, do you think I might spot myself living happily among the orthogonal stars?”
Yalda said, “What if I tell you that I’ve seen the future, and it’s voles all the way?”
Benedetta gestured toward the markets. “Then I can confidently predict that most of those recruits will be gone in a couple of days.”
Silvio stood in the doorway of Yalda’s office. “You need to see this new camp,” he said. “Way out of town.”
She looked down at the calculations Benedetta had submitted on the modified test launch. She’d checked them over and over again, but she still hadn’t made a final decision on whether or not to approve the flight.
“Are you sure there’s a problem?” she asked him. Traders sometimes arrived and set up camp in inconvenient places, but it usually only took them a few days to realize that they were better off in Basetown.
Silvio didn’t reply; he’d given his advice, he wasn’t going to repeat it. It was Eusebio who paid his wages, and if Eusebio put Yalda in charge of the project in his absence then that won her a certain amount of courtesy—but not much.
She said, “All right, I’m coming.”
Silvio drove her a few strolls north along the dirt track that ran from Basetown to one of the disused entrances to the mountain. Yalda didn’t know exactly what he’d been doing there himself; maybe Eusebio had him patrolling the whole area.
There were five trucks at the abandoned construction camp, most of them loaded with soil and farming supplies. A couple of dozen people were visible, digging in the dusty ground. In some respects it wasn’t a bad place to farm, Yalda realized; the shadow of the mountain might well block Gemma’s light enough of the time to allow the crops to retain their usual rhythm, without the need for unwieldy awnings. Having to truck in soil wasn’t promising, but once a crop became established the roots of the plants, and the worms that lived among them, could start breaking down the underlying rock.
Yalda climbed down from the cab and approached the farmers.
&nbs
She caught a few people looking away, embarrassed at the realization that they were being addressed by a solo, but one man put down his shovel and walked over to her.
“I’m Vittorio,” he said. “Welcome.”
“I’m Yalda.” She resisted the urge to make a joke about his famous namesake; either he’d be sick of people doing it, or he’d have no idea what she was talking about. “I work with Eusebio from Zeugma—the man who owns the mines here.” That had become the standard euphemism for the rocket project; everyone knew precisely what was going on inside the mountain, and why, but some people who took a dim view of Eusebio’s whole endeavor were less hostile if they weren’t confronted with explicit reminders of it.
“I don’t believe he owns this land,” Vittorio replied defensively.
“No, he doesn’t.” Yalda tried to keep her tone as friendly as possible. “But if you were hoping to trade with his workers, we have a whole town just south of here where you’d be welcome to set up.” If they signed an agreement with some very reasonable conditions, they could farm just as much land as they were using here, sell their produce in the markets and have access to Basetown’s facilities for no cost at all.
“We chose this location with care,” Vittorio assured her.
“Really? It’s a long way from everything but Basetown, and not as close to there as it could be.”
Vittorio made a gesture of indifference. Other members of his community were watching them discreetly, but Yalda didn’t sense any physical threat, just a mood of resentment at her interference.
“I need to be honest with you,” she said. “In less than a year, this land won’t be suitable for farming anymore.” She was trying to work from the most innocent assumptions she could think of: that the chaos in the sky had driven them off their land in search of some reliable diurnal darkness, and they were unaware of quite how soon it would be before Mount Peerless ceased casting its convenient shadow.
“Are you threatening us?” Vittorio sounded genuinely affronted.
She said, “Not at all, but I think you know what I’m talking about. That you won’t have shade for your crops will be the least of it.”
“Ah, so your master Eusebio will consign us all to flames?” Vittorio made no effort now to hide his contempt. “He’d knowingly slaughter this entire community?”
“Let’s not get melodramatic,” Yalda pleaded. “You’ve barely begun to dig your fields, and now you’ve been informed of the danger so you won’t waste your time putting down roots here. Nobody is going to be consigned to flames.”
“So you pay no heed to the fate of Gemma?”
Yalda was confused. “Gemma is why half the planet has given its blessing to Eusebio’s efforts.”
“Gemma,” Vittorio countered, “taught those of us with eyes that an entire world can be lost to flames. But your master has learned nothing, and in his ignorance he’d blindly set this one alight as well.”
Yalda was growing irritated with the whole “master” thing, but it made a change from being told he was her co-stead. She glanced back toward the truck; Silvio was pretending to be taking a nap.
“You think the rocket would set the world on fire?” If that was his honest belief, Yalda could only admire him for deciding to become a living shield against the threatened conflagration, but he might have dropped by the office and asked a few questions first. “It was a Hurtler that ignited Gemma, and it would take a Hurtler to do the same to us,” she declared.
“A Hurtler, and nothing else?” Vittorio buzzed, amused by her rhetoric. “How can you possibly know that?”
Yalda said, “I don’t know that nothing else could do it—but I know what this rocket will and won’t do. Under the mountain, beneath the sunstone, there’s a seam of calmstone; I’ve been there, I’ve touched it with my own hands. We’ve tested the combination, burning one on top of the other, for far, far longer than they’ll stay together at the launch. The calmstone is ablated by the flame, but there’s no sustained reaction that spreads beyond the site. And before you start protesting that the calmstone is unlikely to be pure, we’ve tested dozens of other rocks as well.”
“And how large was your flame?” Vittorio enquired. “The size of a mountain?”
“No, but that’s not the issue,” Yalda explained. “By holding the flame in place longer in the tests, we can achieve identical conditions in a slab a few strides wide.”
Vittorio simply didn’t accept this. “You’ve played around with some childish fireworks, and you think that proves something. The proof is in the sky.”
“If you’re so impressed by the example of Gemma, how do you propose fending off the Hurtlers that would re-enact the whole thing here?” Yalda demanded. “Thwarting Eusebio won’t spare you from that.”
Vittorio was unfazed. “Do you think there were people on Gemma?”
“No.” This was becoming surreal. “What difference does that make?”
“People can douse small fires,” Vittorio replied. “If one kind of stone is burning, the sand of another kind can be fetched to put it out. If there had been people on Gemma, that’s what they would have done, and that world would not have been lost to the flames.”
Yalda didn’t know how to answer this. To hope that quick thinking and a bucketful of sand could defeat the Hurtlers was absurd… but if you scaled it up to something systematic with teams of rostered observers in every village and whole truckloads of inert minerals at the ready, that might actually contain the effects of a small impact.
“How large is a Hurtler?” Vittorio asked her. He held up two fingers, about a scant apart. “This big? Larger? Smaller?”
“About that size,” Yalda conceded.
“So my choice is between a fire that starts from a pebble, and one that starts from this.” Vittorio turned and gestured at the mountain. “Only a fool would choose the greater risk.”
From the top of the rocket, Yalda could see the wind lifting brown dust from the plain to trace out its eddies and flows. “You can still change your mind,” she said.
“But I’ve already completed the trip,” Benedetta replied placidly. “Time is a circle. It’s happened, it’s over; there’s nothing left to choose.”
Yalda hoped that this fatalist blather was just Benedetta teasing her, but there was no point arguing about it now. The last three of the recruits she’d brought up to ogle the tiny cabin were on the ladder heading back to the ground. Benedetta was strapped onto a bench that had been installed in place of the rack of voles’ cages in the original design; the same cool gases would blow over her body as those that had kept the animals safe from hyperthermia in previous launches. The elaborate clockwork around her that would control the timing of the engines and the parachute’s release had been inspected thrice: by Frido, by Yalda, then finally by Benedetta herself. The voles had only merited two inspections.
“I won’t say good luck then; you won’t need it,” Yalda told her.
“Exactly.”
Yalda couldn’t leave it at that; she squatted down beside the bench. “You know, if you’re made famous by this your co might come looking for you.”
“Whose co?” Benedetta retorted. “Nobody here knows my birth name.”
“No, but how many people as crazy as you could have been born in Jade City?”
Benedetta was amused. “You think I’m from Jade City?”
“Aren’t you?” Yalda had always believed that part of her story. “Your accent sounds authentic.”
“You should hear the other six regions I can do.”
Yalda squeezed her shoulder. “See you soon.” She straightened up then climbed out of the cabin; perched on the ledge above the ladder, she slid the hatch firmly into place. Through the window, she saw Benedetta gesture toward the enabling lever, then make a four-fingered hand: on the fourth chime from the clock beside the bench, she’d launch the rocket. This was the norma
Yalda usually had no trouble with heights, but as she descended the ladder she felt a kind of sympathetic vertigo at the thought of the altitude the cabin would soon reach.
On the ground, she pulled the ladder away and let it fall to one side. The recruits were quiet now; even Leonia was subdued as they started back toward the bunker.
When a gust of wind rose up and sprayed stinging dust into their faces, Fatima said, “Someone should make a truck that runs on compressed air.”
“They should,” Yalda agreed. It had probably been discussed at some point, but then slipped off the agenda; that had happened with a lot of good ideas. Compounding the problem of the project’s sheer complexity, some of Eusebio’s fellow investors had insisted that their funds could only be spent directly on the rocket itself, lest they be viewed as mere secondary players when the descendants of the travelers returned. Yalda found it hilarious that anyone believed that such choices could guarantee them access to the project’s ultimate harvest. If the Peerless really did come back after an age in the void—with the kind of technology that could defeat the Hurtlers and everything that threatened to follow them—they’d trade with whomever they liked, on whatever terms they wished. A certain amount of compassion for their distant cousins was the most she was hoping for; any prospect of scrupulous adherence to contracts signed by their long-dead ancestors was just a fantasy Eusebio had encouraged so the plutocrats could part with vast sums of money without having to confront the horrifying reality that it was actually being spent for the common good.
Frido was waiting by the bunker. “How was she?” he asked anxiously.