“Mind over matter,” said Ava.

“You just have to go for it,” said Alicia, wrapping her arms around herself.

“Well, I’m freezing,” said Finn. “Let’s see if the heater’s working today.”

A few minutes into their return journey, Alicia sat bolt upright.

“Oh my God,” she said, beaming.

Ava laughed.

“I feel great,” Alicia announced. “Oh wow!”

“And that,” said Ava to Finn, “is why I go cold-water swimming in October.”

“And not a single pill in sight.” Finn patted Alicia’s shoulder.

“Why didn’t you come in?” Alicia asked, grinning from ear to ear. “You should try it, everyone should. Next time you are totally coming in with us, seriously… ”

“Can’t. I have an obscure skin condition that means my skin melts in salt water. True story.”

“Your feet didn’t melt.”

“I had them treated with a special coating so I can paddle in the ocean and pass for normal. But it was too expensive to get my whole body done. Also, it turns my skin an unattractive shade of green, and I think that might be why I find it hard to get girls to talk to me. It’s also why I can never have children.”

“Don’t say that,” said Ava.

“It’s all right. I’ll steal one out of an orphanage and raise it in a life of luxury. It’ll work out fine. You’ll see.”

“Where will you sleep tonight?” Alicia asked. “Are we rebuilding the beach hut?”

“Tomorrow,” said Finn. “Tonight we sleep in the van. Or maybe with the fishes. Depends how angry your dad is with me when we get back.”

“With us,” said Ava.

“Nope. With me. I told you, he… ”

“Pas devant les domestiques,” said Ava.

“I’m not a domestique,” Alicia protested.

“No, I know, but you’d be even madder if I called you an enfant.”

“I’m going swimming every single day from now on,” Alicia announced. “I’ll get up before school and swim in the dark.”

“Don’t go in on your own,” warned Ava.

“Remember to watch out for sharks,” said Finn.

The engine hummed to itself as the van drove back up the slow winding hill.

Chapter Fourteen: 2010

“This is a dystopian future,” said Ava, stroking Finn’s hair away from his forehead. “We’re living in a dystopian future.”

“I’m sorry.”

“Don’t be, this is great.”

The airport was a gleaming empty space of white and chrome and glass. Finn lay with his head in Ava’s lap while she leaned against a tall pillar. A fellow traveller might have paused to wonder at the conservatively dressed woman with her expensive shoes and handbag, and the thin scruffy figure in t-shirt and jeans who lay in her lap as if it was the only haven he had ever known. But in these silent early hours, there were no other travellers.

Occasionally they glimpsed tiny figures scurrying between destinations, bringing the tools of their trade (a cleaning cart, a gun, a wheeled suitcase in the colours of their airline). Whenever one of these figures approached an escalator or a travelator, it began to roll, inviting them to change floors or traverse a few hundred feet of floor-space with eerie speed. When their target vanished, they lapsed back into stillness.