I peer round at my companions. They’re sitting in deckchairs, or on towels. In groups chatting, or alone, like me. I’m not the only one nodding off, either.

Several of the men have taken their shirts off, and are holding open beer bottles.

‘Well?’ I say.

‘Why was it necessary to drive such a long way to sit here? The garden at the home is pleasant today.’

‘A change of scene, my dear. Always welcome. Plus here we can see the sea.’

She looks at it.

‘It’s big.’

‘Is that all?’

She shrugs. ‘The waves are interesting. You can deduce a lot about the sea floor and the depth of water from their movement.’

‘No doubt. But the sound and their movement is relaxing.’

‘How?’

‘It’s – I don’t know – hypnotic, maybe?’

She sits and listens and watches. ‘It doesn’t have this effect on me.’

‘I suppose hypnosis is like falling asleep but still being awake. You don’t sleep, do you?’

‘No.’

‘Well then.’

She’s quiet for a bit, then once again, as I’m dropping off, she speaks.

‘I can’t work out the rules.’

‘Rules? What rules?’

‘On the beach, many people are in a state of undress.’

‘Yes.’

‘Why?’

‘They want to feel the sun on their skin.’

‘That is ill-advised.’

‘It feels good.’

‘Very well. Why then don’t people expose their skin to the sun more often? As we drove here, I saw nobody on the streets in a state of undress.’

‘No. It’s not generally acceptable.’

‘People on this beach are wearing special clothes.’

‘Swimming costumes.’

‘They intend to swim?’

‘If they’re brave.’

‘Brave? Are there sharks perhaps?’

‘Probably not. But the sea round England is pretty cold, even on hot days.’

‘Yes, that is the case. Anyway, I see most people are in these costumes on the beach, but there appears to be an invisible line.’

‘A line? Where?’

‘Where the beach ends, or near there. You may not cross it in a swimming costume, it seems. You have to put on at least some clothes.’

‘Yes, true I suppose.’

‘Where are the signs?’

‘What signs?’

‘Telling you this rule.’

I look at her. Is she joking? No, she isn’t. She never jokes.

‘We don’t need a sign. We just know.’

I can tell she finds this is an unsatisfactory answer. Too bad.

She’s quiet again for a minute.

‘Can you explain something else?’

‘I’ll try.’

‘There’s a man and a woman over there. He is wearing bathing trunks. She is wearing a T-shirt over her swimming costume. They have a child with them, and she is naked.’