“Relativity.” She moves her glass of wine aside. “Proxima Centauri is four point two light-years from Earth. If it only took us ten years to get here, we must have been traveling at a reasonable fraction of the speed of light.”

Santi nods. “More time will pass back home.”

“How much more?” Thora unfolds her napkin and holds out her hand for Santi’s pen. “Subjective journey time, ten point four years,” she mutters. “So, twenty point eight years round trip. Assuming constant acceleration . . .” She scribbles down the formula.

Santi leans over, fascinated. “You can calculate hyperbolic sines in your head?”

“To an approximation.” Thora frowns. “Time passed on Earth should be . . . around twenty-three years. Compared to twenty-one for us.” She laughs.

Santi gives her a puzzled look. “Why is that funny?”

“Jules will finally get her wish. When we get back, she’ll be a year older than me.” She stops, correcting herself. “If we get back.”

“We’ll get back.”

Thora meets his eyes. After a long moment, she drains the last of her wine. “Okay. Situation assessed. I’m ready to come up with a plan.”

Santi rubs his temples. “Here’s how I see it. We have an interface with the ship. I suggest we use it.”

“Peregrine?” Thora snorts. “He’s about as much use as a broken toaster. I already asked him to wake us up. Twice.”

“You only asked him one way.”

Thora rolls her eyes. “So we should say please?”

“That’s not what I mean.” Santi leans across the table. Something is wrong: Thora is getting further and further away. “The error has affected his language, right? Maybe if we ask the right way, we can get around his mental block.”

“You’re suggesting we try and argue our way out of here?”

“God knows we’ve had enough practice.” He can’t see Thora clearly, but he can still tell she’s giving him a look. “Let me guess,” he says wearily. “You propose a different approach.”

Thora’s voice comes out of the blur. “I want to go back to the Odysseum. Watch the video, go over every inch of that model ship. There has to be something we can—Santi?”

He goes to rub his eyes, but his hand won’t obey. He tries to stand, but his feet won’t support his weight. He collapses.

“Santi.” Thora’s voice, urgent in the darkness. The cobbles press against his back.

“Thora.” Did you break the world again? She’s shouting for help, and he’s floating, free of the cobbles, free of the restraints around his real body, on his way to the stars.

He wakes in a hospital bed. Thora sits in a chair by the window, biting her nails.

“It’s cancer. Again,” she says when his eyes open. “Brain tumor this time. Inoperable. They’re giving you less than a month.”