The Clockwork Rocket

to do no more than plant crops in an artificial cave inside the mountain, that would be something.

As she stepped away from the desk, a young woman hurried across the foyer toward her.

“I’m sorry,” the woman said. “I wasn’t sure if I should speak to you, but…”

Yalda put down her box of pamphlets. “What did you want to say?”

“I was thinking about your rocket. One thing worries me—” She stopped and lowered her gaze, suddenly shy, as if her words might already have been too presumptuous.

“Go on,” Yalda encouraged her. “If there’s only one thing that worries you, you’re a dozen times more confident than I am.”

The woman said, “When the rocket turns around and comes back toward us… from the point of view of the travelers on the first half of the journey, isn’t it now moving backward in time?”

“Yes it is,” Yalda agreed. “That’s exactly right.”

“And from the point of view of the Hurtlers, and the worlds you think might collide with us… the same thing is true? In the second half of the journey, the rocket will be traveling into their past as well?”

“Yes.” Yalda was impressed; though it was a simple enough observation, only Eusebio and Giorgio had raised it with her before.

The woman looked up, fidgeted anxiously. “Is that… safe?”

“We don’t know,” Yalda admitted. “To what degree the rocket will carry its own arrow of time, embodied in its passengers and cargo, and to what degree its surroundings will influence the arrow… we don’t know.”

“So you’re hoping the travelers will learn enough on the outward voyage to protect themselves on the inward leg?” the woman suggested.

“I suppose it does come down to that.” Yalda had berated Eusebio for relying on uninvented methods of propulsion, but the truth was they had no hope of preparing the travelers in advance for every hazard the journey would entail.

Gaining courage, the woman said, “I’d be satisfied if you could at least be sure that the rocket was heading into the Hurtlers’ future at the start of the trip. If it takes half an age to prepare for the clash, so be it—but having to face that problem from the very beginning would be too much.”

“Satisfied enough… to approve of the venture?”

“Satisfied enough to be a passenger myself.”

Yalda said, “Can I ask your name?”

“Benedetta.”

Yalda took her over to the desk and recorded her details, trying not to let slip that no one else had come close to making such a commitment—not even the recruiter herself.

“Have you studied somewhere?” Yalda asked her. The first passenger of the Peerless had described her profession as “factory worker”.

“In Jade City,” Benedetta admitted reluctantly, as if this were somehow shameful. “I studied engineering, but only for a year.”

“It’s not important, I was just curious.” Yalda heard the forced joviality in her own voice, and struggled to bring the tone back to normal. Asking Benedetta if she were a runaway might frighten her off completely; it was an issue they’d need to deal with at some point—in order to protect both her and the project—but for now all that mattered was that she was keen, and a quick enough thinker to have spotted a genuine problem.

They were alone in the foyer now. Yalda said, “I’m supposed to be out of here before the cleaners come in at midnight, but we can talk for a bit outside if you’re not busy.”

“There’s nowhere I need to be,” Benedetta replied.

Outside, the city was quiet. A dozen slow Hurtlers were spreading their colors across the sky. As the two of them walked away from the hall across the cobblestones, Benedetta said, “Do you really believe that time loops around on itself?”

“I can’t be certain,” Yalda replied. “But I think the evidence is strong.”

“So the future is no different from the past?”

“The real difference is a matter of what we know,” Yalda said. “What information is easily accessible to us. We can know much more about the past than the future, at least if we don’t try to look back too far. But that’s a product of the vagaries of history; there’s no absolute distinction.”

“But then… everything that’s yet to happen is fixed, just as much as everything in the past?”

“Yes.”

“So why are you striving so hard to change the future?”

Yalda buzzed with delight; she should have seen that coming. “‘Change’ isn’t quite the right word,” she suggested. “You can strive to change a bad law—because the law can be different at different times. But either we survive this encounter or we don’t. Whatever the outcome is, no one will change it.”

Benedetta accepted this, but persisted. “What word should I use then? ‘Influence’?”

“I can live with that,” Yalda said. “I’ll own up to striving to influence the future.”

“But how can you influence the future if it’s as fixed as the past? Do you try to influence what happened yesterday?”

“Not anymore,” Yalda said, “but I certainly did the day before.”

“Why, though? If you believe that what happened yesterday has always been fixed, wouldn’t it have turned out the same, regardless?” Benedetta wasn’t teasing her, or playing rhetorical games; she genuinely needed an answer.

“Ah.” Yalda hadn’t had a conversation like this since the long nights she’d spent talking with Tullia—and back then, the roles would have been reversed. “I don’t believe in the kind of predestination that says our actions are irrelevant. So I don’t accept that yesterday would have turned out the same, regardless of what I did.”

“But if your actions aren’t irrelevant, then you can’t be choosing them freely, can you?” Benedetta argued. “If the future is fixed, and your actions affect the future… then your actions themselves must be fixed, otherwise they could lead to the wrong outcome. That means you have no real choice in what you do; you’re just a puppet, steered by forces beyond your control.”

Yalda thought for a while. “Raise your right hand.”

“Why?”

“Go on, humor me.”

Benedetta complied.

“Were you free to raise it or not, as you wished?” Yalda asked her.

“I believe so.”

Yalda said, “Tell me why you should feel any differently about that, depending on whether or not time is a loop and the future is really the distant past.”

Benedetta puzzled over the question. “If it was always going to happen—if in a sense it had already happened—then when I thought I was making the decision, that was just an illusion.”

“An illusion compared to what?” Yalda pressed her. “Tell me how the world could work—how physics could function, how history could be arranged—in a way that would somehow make you ‘more free’?”

“If the future is open,” Benedetta replied. “If our actions are undetermined until we decide what to do.”

“Suppose that really is the case,” Yalda said. “Then what is it that finally determined whether you raised your arm or not?”

“I did. It was my choice.”

“But why did you make that particular choice, and not refuse me?”

Benedetta didn’t reply immediately. “The way you asked, I suppose,” she said finally.

“So I determined your action?”

“No, not completely. My mood, my state of mind played their part as well.”

Yalda said, “None of the things you’ve just referred to disappear from the world if the future is fixed rather than open. Both of us are still here. Our actions are still related in exactly the same way to our wishes, our wishes to our personal moods and histories, and so on.”

Benedetta was not convinced. “If the future is fixed, how can this conversation even mean anything? If it’s an unchangeable fact that I will say whatever I end up saying