The Clockwork Rocket

by Greg Egan

  “We’ve taken three cuttings of goldenrod from each garden and started growing them in a dozen new locations,” Lavinio said. “The transfer was done with all possible care; two separate couriers who’d never been in any of the gardens took each cutting part of the way, and I’ve recruited new people to look after the plants. But realistically, we can’t expect them all to stay free of the blight.”

  “No.”

  “We can’t risk harvesting petals from the cuttings at all, until they’re established,” Lavinio continued. “And it might be unwise to take too many from the original plants either, right now; we don’t want to weaken them unduly before we know that at least some of the new ones have ended up in good condition.”

  “I understand.” For the next few stints there would not be much holin produced; that was unavoidable.

  But Lavinio had done everything possible to safeguard their future supplies. With a bit of luck, the shortage need not be severe or long-lasting.

  Yalda said, “Let me know if anything changes.”

  In the pharmacy, Sefora checked the stock of holin tablets. “We have enough for about seven stints at our current usage,” she said. “There are some petals still being processed, but that will only add a day or two to the supply.”

  Since the launch, every woman on the Peerless had been taking a regular dose of holin that depended on her age, using tables Daria had drawn up that erred on the side of caution. Until now, the gardens had been providing more than enough goldenrod petals to keep the stores replenished; the real limit on building up a larger stockpile had been the shelf life of the drug.

  “Can you draw up new dosage tables?” Yalda asked.

  “On what basis?”

  “We need to stretch out the stockpile—but there’s no point letting the holin sit and go bad.”

  “So… stretch it out how long?” Sefora pressed her.

  “It’s hard to say,” Yalda admitted. “It’s not clear when the gardens will be producing again.”

  “How much are you willing to cut the dosages?”

  “How much can I, without putting people at risk?”

  “No one has those numbers,” Sefora replied. “Holin’s efficacy has never been properly studied, never quantified. All we’ve ever had are anecdotal reports: if you heard of a woman of a given age who wasn’t protected by the dose you heard she’d been taking, you assumed it would be wise to take more.”

  On the Peerless, that uncertainty was meant to have been subsumed by a constant surplus of the drug—and with four bountiful gardens, that should have been possible.

  “I suppose it’s too late to start testing it on arborines,” Yalda lamented.

  “That would take years,” Sefora agreed.

  “Not to mention some actual holin we could spare.”

  Sefora said, “I’ll draw up dosage tables that will let the stockpile last ten stints. Any longer than that, and I wouldn’t trust the quality. Do you want me to make any exceptions?”

  “Exceptions?”

  “If we cut the older women’s doses in strict proportion to everyone else’s,” Sefora explained, “I can’t promise that they won’t face a greater increase in risk.”

  Yalda said, “You mean a drop of three parts in ten could be enough…?” She pictured Tullia, lying motionless on the floor of her apartment. No one had the numbers, but they all had their fears.

  “I could always leave the dosage for the senior women unchanged,” Sefora said. “If we made an exception for everyone older than a dozen years and ten, that’s less than a sixth of the female population. Spread out between all the younger cohorts, the difference would scarcely be noticeable.” She was not quite as old as Yalda, but she would fall into the same category.

  Yalda considered the suggestion. Wouldn’t it be fairer, to protect the most vulnerable members of the crew? It would certainly be prudent: they couldn’t risk having the most experienced women taken without warning, leaving the Peerless drifting aimlessly through the void.

  She said, “I think you should do that.”

  “If a particle is moving in an energy valley that takes the form of a parabola,” Yalda told the class, “it will repeat the same harmonic motion over and over, with a frequency that depends only on a single number describing the parabola’s shape.”

  “Like a weight oscillating on the end of a spring?” Prospera suggested.

  “Or a pendulum under gravity?” Fatima added.

  “In idealized versions, yes,” Yalda agreed, “though in reality both those systems experience friction, and both have small deviations from a parabolic potential.

  “Still, in the absence of friction—or light generation—the particle’s energy will be conserved, and if it’s moving back and forth in just one dimension, even if the valley isn’t shaped like a parabola the particle will always return to its starting point. So its motion will be perfectly cyclical, and it won’t have any harmonics with a lower frequency than that cycle.

  “But in two or more dimensions, things start to get more complicated. Even when energy is conserved, a particle need not retrace its path exactly. If the shape of the valley is a perfect paraboloid it will do so—” Yalda sketched an example:

  “But that’s not the case for the energy valley in a solid, due to Nereo’s potential. There, the cross-section isn’t exactly parabolic, and it will be shaped a bit differently when you slice it in different directions.”

  “So instead of moving back and forth with a single, pure frequency, a luxagen in this energy valley will follow a path that we need to describe with a multitude of different frequencies, all present in different amounts.”

  “Like describing the strengths of all the colors in a flame?” Ausilia asked.

  “Very much like that,” Yalda said. “What we’re going to be doing, eventually, is trying to predict both the colors of solids in ambient light and the spectrum of the light that we’d expect them to emit. And then the question will be: why are our predictions so wrong? Why does it actually take some kind of disruption for solids to start emitting any light at all?”

  After the lesson, half the class moved to the food hall, unwilling to end the discussion. Yalda watched the young women among them swallowing their two tablets of holin with their loaves; each cube was smaller on its side than the old ones by just one part in six, which made the rather greater reduction in its volume almost invisible. But she’d taken her own dozen full-strength cubes in the privacy of her apartment, ashamed of the discrepancy even though it was unlikely that anyone would have noticed it.

  Yalda listened to the students’ excited chatter and answered their questions with care. Who else could have taught them harmonic analysis of Nereo’s potential, if not her? Who else could have set them on the path to a future where everything the Peerless would need in order to survive its exile and return in triumph was finally understood?

  Isidora. Sabino. Severa. Perhaps a dozen people in all. She was not indispensable.

  Fatima lingered after the others in the group had gone. “Have you thought any more about Nino?” she asked Yalda.

  “You know I’d be happy to free him,” Yalda replied. “But to do that, I need to be in a position of strength. I’m sure Nino understands that.”

  Fatima was unmoved. “You rescued the crops and swatted away the orthogonal dust with the same hand! Everyone knows that they owe their lives to you. How much stronger do you think you’ll ever be?”

  “This goldenrod problem—” Yalda protested.

  “That’s hardly your fault.”

  “Whether it is or it isn’t, people won’t be happy until it’s resolved.” Suddenly self-conscious, Yalda looked around the hall with her rear gaze, but no one was paying them any attention.

  Fatima said, “There’ll always be something. If you just saw Nino, if you spoke with him—”

  “Anyone else would have gotten rid of him by now,” Yalda declared irritably.

  Fatima regarded her with disbelief, then
lapsed into a reproachful silence.

  Yalda said, “I didn’t mean that. I’m sorry. When things have improved, I’ll look at his situation again.”

  “You were in prison once, weren’t you?” Fatima replied. It was a rhetorical question; she knew the answer. “Waiting for someone to set you free?”

  “I won’t abandon him,” Yalda said. “I promise you that. Just let me find the right time.”

  “Ten of the goldenrod cuttings are infected with blight,” Lavinio announced. “The other two appear to be healthy. But those two cuttings are all we have now; the plants in the four main gardens are lost.”

  Yalda absorbed the news, and tried to think through the consequences calmly. They would not be able to harvest any petals from the cuttings until they’d grown larger, or they’d risk killing the plants. It could be as long as half a year before any more holin was being produced—and after that, it could take another year or two for the rate of supply to return to normal.

  “What if you split each cutting—after a few stints—and grew the halves separately?” she suggested.

  “That would just delay the time until they were strong enough to survive harvesting,” Lavinio explained. “The most important thing is keeping those two plants strong and uninfected.”

  “I understand.”

  “We’re lucky we haven’t lost the goldenrods completely,” Lavinio said bluntly. “If we’re not careful, it might yet end that way.”

  When he’d left, Yalda clung to the ropes beside her desk, fighting a growing sense of helplessness. Word of how serious the problem had become would not take long to spread; if she failed to deal with it swiftly there’d be chaos.

  Rationing the stored holin more severely wouldn’t help; there was no point eking it out so slowly that it began to lose its potency. The only way she could survive the wait until production started again was to commandeer enough of what remained to increase her dose as time went on, to compensate for the drug’s deterioration.

  But then even when the holin was fresh again, there would not be enough to go around.

  She could ask Sefora to draw up a plan to save the oldest women, leaving the others to take their chances. No one on the Peerless was a child, though; no one would be immune to the risk. The shortage would take its toll across the mountain—while the drugs that kept each old woman alive could protect half a dozen of their younger crew-mates.

  Yalda struggled to clear her mind. How was she meant to weigh up the choices and reach the right decision? Eusebio had given her Frido to share the burdens of leadership, but she’d destroyed any chance of trust between them, any hope of getting honest advice from him.

  She dragged herself along the ropes to the front of the office and pulled the doors closed. She let her body relax completely, then she felt herself begin to shiver and hum.

  How close had she come to snatching a few more years for herself, by risking the futures of all the young women who still had their lives ahead of them? How close had she come to stealing the hard-won promise of Prospera, Ausilia and Fatima—Fatima who’d never shown her anything but loyalty, who’d had the love and courage to pluck her from the void?

  What had she imagined her own role would be? To see the journey through to the end? To return to Zeugma to share the triumph with Eusebio, and join in the celebrations with all her lost friends? She’d made her choice: she’d been vain enough to believe that the Peerless needed her. But it needed her only to set its course; everything else belonged to the generations to follow.

  Yalda composed herself. Once her body was still again she felt calm and lucid.

  She’d played her part, and it was almost over. But now she knew what needed to be done.

  Isidora’s co worked in the pharmacy, and he’d done the same job for eight years back home. Yalda met him to gauge his loyalties. While Sefora was in charge he would follow her instructions, but he accepted Yalda’s right to replace her. And he did not want his own co to lose control over her body.

  Yalda picked a dozen young women to accompany her. They made their move a bell before the main shift began; none of the junior pharmacists put up any serious resistance, and by the time Sefora came on duty Yalda’s team had the holin store surrounded.

  “Are you going to punish me for doing what you asked?” Sefora demanded angrily. She looked to her colleagues for support, but they wouldn’t meet her gaze; they were backing the new guard.

  “I’m not punishing you at all,” Yalda replied. “You served the Peerless well, but now this job needs someone new. You can retire to a life of ease.”

  “Really?” Sefora emitted a mirthless buzz. “Is that what you intend doing yourself?”

  Yalda said, “You can hear about my plans at the meeting, along with everyone else.”

  Yalda surveyed the faces of the assembled crew. “I wish we had holin for everyone in the mountain,” she said, “but that’s beyond our control now. So the time has come for the women like myself who would use the most of it to step aside, and leave what remains to those who have the most to lose.”

  She listed the replacements for a dozen senior positions. A trace of discontent rippled through the crowd, but she could see expressions of acceptance, too. There was no painless way through the shortage, but any other scheme would have ended in insurrection.

  “On the question of who should take my place as leader,” she said, “everyone knows there is an obvious choice.” Yalda stretched out an arm toward Frido, who was clinging to a rope near the front of the hall. “But before I appoint my successor, I need to ask him if he’s willing to meet some conditions.”

  Frido said, “Tell me what you want.”

  “When I step down,” Yalda said, “I want the right to choose my own co-stead. And when I’m gone, I want my family to be left unharmed. I want my co-stead and my children to be given your respect and protection, and to suffer no revenge.”

  Frido regarded her with an expression of wounded horror. “What kind of monster do you take me for? Yalda, you have the love and respect of everyone here. No one will harm your family.”

  “You give me your word, before the whole crew?” she insisted.

  “Of course. Everything you’ve asked for, I promise it will be done.”

  Yalda had no idea what was going through his mind, but what else could he have said? She’d just granted the young runaways the best prospects they could have hoped for to make it through the holin shortage. If Frido had so much as hinted that he expected to assert some bizarre, paternalistic right to veto her choice of co-stead, they would have torn him apart.

  She said, “Then it’s done. I resign the leadership in your favor. If the crew accepts you, the Peerless is in your hands.”

  Frido moved forward, toward the stage. Behind him, half the crew began chanting Yalda’s name—affirming her decision, not rejecting her successor, but it still made Frido flinch.

  Watch your back, Yalda thought. Get used to it. That’s what your life is going to be like now.

  20

  Fatima moved ahead of Yalda down the center of the stairwell, pausing now and then to allow her to catch up. Yalda didn’t mind being hurried along this way; if they’d been traveling side by side they would have had to pass the time discussing the reason for their journey.

  When they came to the first radial tunnel, Fatima let herself free-fall most of the way, only snatching at the rope ladder when she began to veer away from it. Yalda declined to follow her example, and descended slowly, rung by rung. The locked doors they encountered along the way did not appear marked, let alone damaged. No one had been sufficiently motivated to try to assassinate the half-forgotten saboteur.

  In the abandoned navigators’ post above the second-tier engines, Yalda waited outside the cell. Nino trusted Fatima, so it was best that he hear most of this from her. But after a few lapses, she invited Yalda in.

  “Hello, Yalda.” Nino hung in the center of a sparse network of ropes. He was much thinner than she remembered
him, and he kept his eyes averted as he spoke.

  “Hello.” The cell was crowded with books and papers. As in Yalda’s own apartment their not-quite-weightless state would make them difficult to manage, but the place had been kept scrupulously tidy.

  “Fatima explained your proposal. But she wasn’t able to say what would happen if I refused you.”

  “Nothing is by force,” Yalda said. “Whatever you choose, I’m willing to take you to the summit and do my best to protect you.”

  “I don’t know if I could look after myself up there,” he said. “Let alone… anyone else.”

  Fatima said quietly, “I’ll help.”

  Nino seemed paralyzed, unable to reach a decision. How could any of them know what was or wasn’t possible? Yalda surveyed the papers stacked against the rear wall. “We can come back for these later,” she said. “Unless there’s something you need?”

  Nino buzzed softly. “I never want to be in the same room as the sagas again.”

  Outside the cell he faltered, gawping at the preposterous spaces around him. Had Fatima never broken the rules and let him out during a visit? Perhaps he’d refused, afraid that even a small taste of freedom would make his imprisonment too hard to bear.

  On the journey back Fatima was patient, demonstrating to Nino how to negotiate the changing forces on his body. Yalda looked on, trying to be equally encouraging herself, but wondering if she’d made a terrible mistake. Nino might learn to be agile again, but what had she done to his spirit? When she’d been teaching him, she’d had no doubt that his memories of his children were keeping him sane. But he’d spent more than three years excluded from any kind of normal life—and she still didn’t know if he’d be accepted back into the community of the Peerless.

  When they left the central stairwell in the academic precinct, Nino blinked and squinted at the lamps around them as if he’d been thrust into the searing blaze of noon. When the first passerby looked their way he stopped moving and clutched the ropes tightly with four hands, his posture growing cowed and defensive. Yalda watched the woman’s expression change from confusion to recognition, then from shock to comprehension. As she passed them on the opposite ladder she glanced at Yalda with what might have been an acknowledgment of her audacity, but exactly what fate she wished for the happy couple was impossible to discern.