‘I’m OK. It’s nice to be of use.’

‘Thank you.’ And Will sat with her and talked about school, about his fundraising efforts for the library, about the girl he likes. She was easy to talk to. She understood what was in the spaces where he said nothing.

The party’s in full swing now. Will hasn’t seen Alfie for a while, although for once there’s no pang of jealousy at the thought of him having fun with other people. Whether he’s been gone ten minutes or an hour it’s hard to tell – the evening seems somehow jumbled. And in any case, things that are now in the past feel oddly irrelevant, much as the future does. He hears someone utter the word tomorrow and he’s struck by what a distant, abstract concept that is. It’s now that really matters, Will is thinking. This unit of time is more valuable than any before or after.

An image pops up, in his fizzing brain, of a massive zip, weaving from side to side like a ski run. And everyone’s standing on the slider as it zooms along, locking the separate sides of the zip together. That’s us, Will thinks, pulling all the possibilities together into one solid track – the past behind us, locked together, the future waiting for the now to get to it, to pull all the possibilities into line. There we all are, in the now, at the very frontier where all that’s possible is gathered in, reduced to one unarguable history. And the image melts away, and Will can’t quite remember what it was he was thinking about.

He steps out on to the deck, gazing around for more people who he can drop into effortless conversation with, as he’s been doing inside. A DJ pumps out house music. Will grooves to the beat as he wades through a haze of weed smoke, which flashes blue and purple in the disco lights.

‘Hey, big man,’ a voice says.

‘Hey,’ Will replies, his voice so warm he barely recognizes it as his own. He looks the guy up and down. He’s eighteen or nineteen, smooth-skinned, hair set in a quiff. Maybe he’s come as James Dean. Or perhaps that’s just how he dresses.

He’s so close his cheek almost rests on Will’s shoulder blade. ‘There’s a steam room,’ he says. ‘By the pool.’

Will forces himself to focus. The pool is well subscribed now, the surface foaming as bodies dance and writhe against each other. Beyond, there’s a log cabin, glowing in UV light. ‘Right.’

‘Want to join us?’ the guy asks. A step behind him stands a girl with jet black hair, a stripe on the left side of her head shaved to skin. There’s a faraway look in her watery blue eyes.

‘Are you guys together?’ Will asks.