‘Who cares? We’re on holiday. If they’ve got oysters, then that’s what I’m having. The most sensuous food in the world.’ He turned his wide smile on Irene. ‘This is the life.’

Then, without warning, Mickey stripped off his shirt and ran whooping off the edge of the boat, crookedly flying through the air, arms akimbo and legs running wildly mid-air, before hitting the water with a splash, coming up into an untidy crawl.

‘There are jellyfish,’ said Neil. ‘Should we swim if we might get stung?’

But Irene already stood on the edge of the top deck, hesitating. It suddenly looked a long way down.

‘Come on, all you cowards!’ cried Mickey. ‘Jump.’

She took a breath and jumped, feet first, and for a moment was going straight down into the murky green, able to make out nothing except the dim crowds of jellyfish all around her, dozens of translucent lungs. Then she surfaced, mosquitoes sticking to her cheeks. She wiped them off and laughed up at the faces peering down from the upper deck.

‘I want to go in,’ said Katherine.

‘Not from the boat – and not with those jellyfish.’

‘I want to!’

‘Not now. Look, Mummy’s about to jump.’

Lorrie wore a red bikini and goggles; her hair was tied back in a ponytail. She raised her hands and dived into the lake, clean as a knife, leaving a small circle where her feet had disappeared.

‘Mummy!’

‘Look for where she comes out.’

‘I want Mummy!’

Lorrie came up, lifted her hand in greeting, then turned her back on the boat and set off in a steady, straight-backed crawl. Everyone watched her go. Mickey clambered aboard again, Irene lay on her back in the water, sculling and watching the blue sky with its far-off mountains of billowing clouds. A few moments later, Neil was in the water too, swimming with a skew-kneed breaststroke after Lorrie, his head, like a retriever’s, lifted eagerly out of the water.

Mickey launched himself once more into the water, hitting it with a tremendous thwack, then setting off, more energy than motion.

‘Daddy!’ yelled Katherine. ‘Mummy! Don’t leave me!’

Luke held her hand firmly. ‘They’ll be back soon. Watch.’

‘Mummy.’ She was weeping now, and tugging away from his hands.

‘Listen, Katherine. Look through these binoculars. I’ll hold them and you just look, like that. There. Can you see them? They’re fine. The water holds them up, see? And soon they’ll be back with you and you can go swimming from the shore.’

‘I want them.’

‘You’ll have them soon.’ His tone was quite patient. ‘They’re having a nice time.’

‘I want them now!’

‘I know you do, Katherine. But you have to wait a few minutes. Wait with me and we’ll watch them come back again.’