He shrugged. ‘I found this lot in a cupboard and thought Jimmy might like it.’ I was still hesitant, but Kit was not to be dissuaded. ‘Look, I know you’re worried about Eli, but we can talk later. Let’s have a bit of fun as well.’

So we dressed my brother in the costume and tied red kerchiefs around our own heads. When we looked at ourselves in the mirror, Jimmy laughed so much that he went red in the face, and his clear enjoyment was somehow infectious. I began to loosen up, too.

‘Yo-ho-ho, me hearties,’ Kit shouted as we ran to the boathouse – Jimmy holding on to his hat and the parrot with both hands. ‘I’ll take Captain Hook here with me in the Mary Jane, though of course she’s the Jolly Roger today,’ Kit said. ‘You take Robin and try to find us. You’ll have to wait ten minutes to give us a head-start, though, cos this old thing’s so slow.’

He put a hand on Jimmy’s shoulder. ‘Come with me, Cap’n. Let’s weigh anchor and hoist the mainsail.’ As they rowed away, Jimmy waved his sword and, noisily encouraged by Kit, approximated shouts of ‘Yo-ho-ho and a bottle of rum’ over and over again.

It was obvious that they were heading for Pirate’s Lair, and after five minutes I climbed into Robin and began rowing in that direction. Sure enough they had already landed, and I pulled up Robin and pretended to corner them. Kit and I had a sword fight with sticks, with Jimmy excitedly shouting encouragement from the sidelines, before Kit surrendered and we all fell to the ground in a heap, laughing uproariously. I was exhausted, hot and sweaty, but hadn’t had so much fun in years.

Once we’d recovered, Kit sent Jimmy searching for the treasure he swore he’d buried on the island some years before. ‘Look for the pile of pebbles,’ he said. ‘It’ll be under that.’

‘Really?’ I asked. ‘Is that true? I hope you’re not teasing him.’

‘Yes, really. I buried some old bits of jewellery my mother gave me in a cigar box, and marked it with stones. That was a few years ago, but I expect it’s still there somewhere.’

With Jimmy gone, we were alone, sitting side-by-side on the rickety old landing stage, our feet dangling in the water. It was so hot that even the birds seemed to have taken cover: not a single coot, moorhen or duck was to be seen, and there was no song from the trees. Willow fluff floated, barely moving, on the air. Insects skimmed across the surface of the water below us; the ghostly forms of tiny minnows approached our toes and disappeared in an instant with the slightest twitch.