It had become a routine, though one never agreed out loud. They tended to meet at the Men’s Pond – or in the Men’s Pond, as Nicks would usually be submerged already. They’d swim, do some diving, and then sneak into the Not Allowed Pond. Nicks would only be in his old-looking trunks and never had any bags with him or even shoes – he must just run out of the back door of his house. He would laugh at Matty’s goggles, ones that someone had left hanging up in the changing area, and ping the elastic at the back, hard.

The cold was no longer a shock but something to look forward to. Matty was getting stronger, exhaling underwater like you were supposed to, stretching arms out in front crawl. A forward somersault, water rushing in. Nicks swam strangely, like he was an eel, arms by his sides, often going underwater for ages and popping up again in a completely different direction from where you’d expect, or surfacing right behind Matty, bearing gifts. A water-boatman on his palm. Cotton-fluff. A frog once, its pulse beating in its throat. He would get really close to the moorhens and the mallards, almost enough to grab them, and they’d flap away squawking at the very last minute, Nicks squawking back.

Matty would wade through the mud as if there were rice paddies all around and not English trees, the dragonflies now helicopters firing napalm to the sound of loud orchestral music with trumpets blaring. Or would try to beat the world record for holding your breath underwater. The longest time in the Guinness Book of Records was 13 minutes and 42.5 seconds. But it was impossible to get past even a minute.

If Nicks wasn’t around, Matty would swim in one narrow circle around the Men’s Pond and then sit on the floating platform and watch the divers. There were all sorts of swimmers. City workers in their suits, taking their ties off. Orthodox Jews, the ends of their peyos going springy. A particular group sat on the weightlifting apparatus in the middle, men with massive arms and massive thighs, either lifting the weights or watching them be lifted.

Matty listened to people in the changing area. A butcher talking about getting a really big cow into the abattoir and his meat-saw being too blunt, and a man who drove a delivery van around London in half the time he was supposed to so that he could come here. But often everyone was quiet, just reading or drying off, simple hellos and comments about how cold the water was, or how it was better than yesterday by a degree. Hardly anyone ever took any notice of the kid in the corner, as if Matty was just as much part of this place as the damp concrete and the moss felting the corrugated iron walls.