He meets her eyes. “In a heartbeat. I can’t imagine a better reason to lay down my life.”

“Then why won’t you let me do it for you?”

His mouth moves, struggling to let something out. “It’s not fair,” he says finally. “It’s not fair to compare how I would act in this situation to how you should act. My beliefs—I—”

Thora smiles. “Oh, I get it. You mean because I’m a godless heathen? You think it’s harder for me to risk myself because my life and death are meaningless anyway?”

“I didn’t mean—”

“I told you. I make my own meaning. No, I don’t think I’m going anywhere after this. I don’t think God is watching, and I don’t think there’s a cosmic plan that my death is designed to fulfill.” She looks up into her own sleeping face. “Honestly, I’m angry about it. I’m angry that I might never meet Jules—the real Jules. I’m angry that there’s an entire new world out there, just—right there”—she reaches out, as if the planet is hovering on the other side of the darkness “and I may never get to see it.” She meets Santi’s eyes, warm and bright and terrified for her. “Butif it means you live, and see it for both of us—that’s meaning enough.”

“No.” He shakes his head. “No, I won’t do it. I won’t let you go.”

Thora’s heart beats like a fly trapped in a glass. She traces the lines of Santi’s face, wipes the tears that are already starting to fall. “Do you know why I’m smiling?” she asks.

He chokes, shaking his head.

“Because I have a knock-down argument, and it’s going to destroy you.” She looks into his eyes. “Who are we, Santi?”

He understands. He turns his head, tries to pull his hands away, but she holds on. “You know who we are. We’re explorers. Both of us, always and forever.” She squeezes his hands, rests her forehead against his. “We gave up everything for this. Our loved ones, our futures, our whole lives. All for the possibility of a new world. Are you telling me either of us would draw the line here? Say, no, this is too much, it’s not worth it?”

He stares at her, across the space that contains only them. Versions of them spiral out from this moment, and Thora finally understands: they all exist, every one of them, no matter what happens next.

“No,” Santi says, his voice broken.

She shakes her head against his. “This is what we were always for. To touch the unknown, or die trying.” She smiles. “Even if I never see it, I’m glad I got to make it this far.”

They walk slowly back across the night-lit bridge, through the small-hours quiet of the old town.

“We don’t have to do this now,” Santi says. “We have a few more months. We could live them, first.”

“You really think I could live like that? With my death hanging over me?” Thora looks at him. “I know what you’d want, if you were me. A farewell tour of your favourite haunts. A heart-to-heart with Héloïse and your parents. A series of murals summing up the meaning of your existence.” She looks away from his rueful smile. “But that’s not me. I’m taking one last look at the city, and then we’re doing this.”One last look.Thora pushes down what she’s really afraid of: if she has time to think about it, time to slow down and look her decision in the face, she might change her mind.

They take their time climbing the tower. Thora tells herself they’re being careful. She knows what they’re really doing is pushing back the moment when they will have to say goodbye.

At the top, they sit side by side looking over the city: the cathedral, the river, the Hohenzollernbrücke covered in beautiful foolish gestures of love. Thora closes her eyes to a vision, clear as a gift: Santi stepping onto the surface of a new world, its dust rising to welcome his feet.

“Bury me there,” she decides. “If I don’t make it.”

“Where?”

She opens her eyes to Santi’s beloved, shattered face. “On the new world.”

He takes a long breath before he speaks. “If that’s what you want.”

She frowns at the implication. “What, would you want your corpse hauled back to Earth? I assume the training we can’t remember included briefings on cargo efficiency.”

He shakes his head, looking up with a soft smile. “No. No, I’d want to be buried among the stars.”

She snorts. “You mean drift forever through space as a human icicle? Whatever floats your boat.”

Behind his smile, he’s starting to cry again. Thora feels herself buckling like a tin in a vacuum. If she doesn’t do this now, she won’t have the strength. “Peregrine!” she yells, her voice ringing out.

Nothing happens. She looks uncertainly at Santi.

“Can he even come up here?” he wonders.

“I was kind of expecting him to float down from a cloud, if I’m honest.”