The beach at Cap d’Agde was crowded.

The Mediterranean was a brilliant, sparkling blue, small waves whipped up by a gentle onshore breeze that brought a note of coolness to the merciless midday sunshine. Our little group was subdued after last night, our towels grouped around a pair of large parasols, bags and books and a big blue cool box piled at the centre of our encampment. The smell of suntan lotion mingled with a salty breeze off the sea and cigarette smoke drifting over us from a French couple nearby. I rubbed suntan lotion into Lucy’s back and shoulders as she held her long blonde hair out of the way with one hand, thumb-typing on her mobile with her other. I was glad to be here, glad to be distracted – in the thick of things – rather than back at the villa, letting my mind wander to dark places. I felt as though I was living in some TV drama, and everywhere I looked a camera was zooming on each of my best friends’ faces, shouted accusations coming one after another.

Is it you? Or you, or you?

Sean had been more attentive than usual, carrying bags, setting up umbrellas, fetching chilled water and snacks for me and the kids. Was he trying extra hard because of what he’d done? What he was still doing?

Jennifer was beside me on a large straw mat, propped up on her elbows, surveying the packed beach around us. A serious-looking paperback – The Optimistic Child: A Revolutionary Approach to Raising Resilient Children – lay untouched on the sand next to her. She had been a star athlete when we met, playing tennis and hockey in the national university leagues. At five feet ten, she was the tallest of the four of us and had managed to maintain a lean, strong physique with a weekly routine of tennis, Pilates and jogging. There had been a time when I didn’t particularly enjoy being next to her on the beach, or at the pool, or anywhere in a swimming costume. I was the pale Englishwoman, always trying – and never quite succeeding – to get back to my wedding day weight, next to this toned, tanned Californian who never appeared to put on a pound.

I thought I had got over that particular insecurity. Maybe not. It seemed to have returned, with a vengeance, today.

‘We seem to have chosen the wrong day to come to the beach,’ I said. ‘It’s like half of Béziers is here.’

‘Isn’t Cap d’Agde supposed to be a nudist beach?’

‘That’s around the headland, a bit further up. Why, do you fancy it?’

Jennifer laughed. ‘Are you kidding me? Lots of old guys with their junk hanging out? Ee-yew.’

‘Better a busy beach than a naked beach, then?’