“I didn’t want you to have to do this,” mumbled Finn. “I didn’t even write to you in case I put something that made you think… ”

“That’s how I knew. You always write.” Finn stirred restlessly in her lap. “Shh. Lie still. You need to rest.”

“I had that dream again,” said Finn. “We were on the beach, just down from the dunes. I think we were living there. Do you remember when we were kids… ”

“Of course I do.”

“There was a huge wave coming in, just rolling in like a tsunami. I was terrified, but you were totally calm. You said, ‘Don’t worry, I’ll protect you.’ And just as it was about to break over us, I woke up and the police officer was leaning over me and grinning and telling me I’d got a visitor. Ava, I’m so sorry.”

“Look at that escalator. It’s gone quiet again. How does it know?”

“There must be a sensor.”

“Yes I know, but is it in the ground or on the ceiling or what? Or maybe there’s a gnome in the basement with CCTV and a big red button.” She stroked his hair again. “Do they have gnomes here?”

“I don’t know. Yes, I think they do, but they’re not called gnomes, they’re called something else, I can’t remember.”

“Don’t be so angry with yourself.”

“But I am angry with myself. I’m furious. I’m too old to need rescuing. And you’ve got better things to do than chase after me. You need to live your life and let me get on with living mine.”

“D’you know, you sound exactly like… ”

“Like Paul?” Finn’s smile was like the faint sad ghost of his younger self. “How about that? It’s almost like he wrote me a letter and put it in my backpack for me to find and I’ve been carrying it around ever since.”

“He did that?”

“Only sensible thing he’s ever done. That and marrying you, of course.”

“But why would he?”

“Because just for once, he had a point and every word he wrote was true.”

“Of course it’s not true. He just… ”

“… doesn’t like me, I know. No, it’s all right. I know he doesn’t. He never has. He thinks I’m a bad influence. Does he know where you are?”

“Not exactly. I told him I’d be gone about a week.”

“But he knows you’re chasing round the world trying to find your idiot little brother.”

“You’re not an idiot.”

“Course I’m an idiot.” Finn shivered and coughed. Ava laid a hand on his forehead.

“Your temperature’s going up again. As soon as we get back you’re going to the doctor.”

“I’ll be fine, I’ve had it for weeks. It’ll go in the end.”

“Are you taking anything for it?”

“Nothing I can bring through airport security. It’s all right, don’t look like that, I haven’t got anything on me, of course I haven’t. You don’t think I’d do that to you, do you?”