‘Let me,’ said the boy in the red shorts. I handed the shell to him; he clamped it to his ear and shook his head. ‘I can’t hear anything.’

‘Let Robert try,’ I said. The sun was warm on my shoulders, and the sea air seemed to have cleared my head of all memory of this morning.

But the boy ignored me, threw down the shell and sorted through the others in his collection, balancing them, one on top of the other, in little piles.

I handed another shell, almost as big as the first, to Robert. ‘Try it.’

He took it and held it briefly by his ear before shaking his head.

‘Closer,’ I said. ‘You have to hold it closer. Or the sea won’t reach.’

Just then, the other boy upset his piles of shells. They clattered on deck and the boy began to wail.

But my son didn’t move. He kept the shell to his ear while I shielded his eyes and watched him.

‘I can hear it,’ he said.

The boat chugged beneath us; the sea was a calm pond. Brownsea was sandy, full of gorse. The rich smell of the shrub rose up in the heat, mingling with the sweat of hundreds of families searching for shade. Many of them, denied the use of cars, had flopped out on the nearest strip of grass by the harbour, and I knew they would still be there when we returned to the ferry.

But we would walk further. As we walked, we passed shirtless men in shorts, lying on what was left of the scorched grass. Women rested their heads on their husbands’ naked thighs, chests or stomachs, and stroked their exposed skin. Couples smiled and sweated together as their children played somewhere within earshot, their shouts softened only slightly by the fierceness of the sun.

I had read that the most beautiful part of Brownsea was the north-east beach, and I intended to take Robert and Kathryn there – it was about a thirty-minute walk – although I hadn’t yet mentioned it to them.

After ten minutes of walking along the gravel trail, Kathryn said, ‘Shall we stop here?’

‘Can I have an ice cream?’ asked Robert.

‘We’re not there yet.’

‘I’m hot,’ said Robert, and his mother knelt before him and wiped his forehead with her hand.

‘I’d like an ice cream, Howard,’ said Kathryn, standing up and touching my arm. ‘I think I saw a van back there.’

‘All right.’ I smiled. ‘One each, then.’

Kathryn had a Midnight Mint. It was her favourite, dark chocolate encasing cool white ice cream. She ate it carefully, as she always did, nibbling off a section of chocolate before licking out the ice cream within.

I had a 99 cone, as did Robert. When I asked him if his was good, he nodded without bothering to stop licking.

‘Let’s sit for a while,’ said Kathryn, pointing to a grassy area beneath some trees.

Kathryn sat with her head in the shade and her legs in the sun. I propped the picnic bag against the trunk.