Thora wonders how he pulled this sleight of hand, turning a joke into an earnest discussion. Part of her doesn’t care. For the first time tonight, something is coming through. “Where’s your evidence?” she demands.

“My parents. They’ve been married thirty years, but my father still discovers things about my mother that shock him.”

“Really,” Thora drawls. “Does your mum say the same thing about your dad?”

He looks confused, then wary. “Why?”

“Because that’s a classic thing men say when they don’t want to engage with women as people. Oh, she’s such a mystery, when she’s been telling you for the past thirty years what she wants and you just haven’t been listening.”

Santi smiles, but there’s an edge to it. “Maybe your parents are like that.”

“Oh, no. My parents have learned all there is to know about each other.” Thora pulls her scarf tighter against the cold. “Forget finishing each other’s sentences. These days they can skip entire conversations because they already know how they would end.”

Santi vaults the railing and offers her his hand. “But that doesn’t mean they know everything about each other. Sure, they know their relationship, but they still only know each other from one—I don’t know how to say it. From one side.”

Thora ignores his hand and climbs the railing herself. “What do you mean?”

“I mean, they only know each other as husband and wife. They might say things, do things, with their friends, even with you, that they’d never show to each other.” He shrugs. “You can’t ever know someone completely. You’d have to be everything to them, and that’s impossible.”

They’re at the foot of the tower, where the stones bloom with graffiti: layers of words in pen and paint, an unreadable palimpsest in a dozen languages. Thora looks up. The tower is higher than she thought. Santi gives her a look like he’s expecting her to back out. It’s that, more than anything, that makes her step through the jagged gap in the wall.

Out of one world, into another. She expects to have lost Santi on the way, but he’s with her, his breath the only sound in the universe. They look up into darkness studded with points of light. Through the hole at the top, the surviving roof tiles mask a glimpse of stars.

Thora steps onto the half-crumbled stairway that winds up the inside wall. She looks back at Santi. “So we’re doing this.”

He grins. “Why not?”