And then the shadow vanished, and there were just the three of us.

I decided not to mention it. I had a feeling that even if either – or both – of them could have explained what I’d seen, they would pretended to have no idea. They’d have made out I was just being weird. And if they really didn’t know, they’d start to have serious doubts about my grasp on reality.

Ava was by the hotel pool, lying under a sunshade in her bikini. She was wearing her sunglasses and she looked grown up and glamorous, like a film star in disguise who wouldn’t bother about the kinds of things that worried ordinary people.

Mark went off to get drinks for us and Mum took the sun lounger on one side of Ava and I took the other.

Ava said to me, ‘Did you swim?’

‘I paddled.’

‘Chicken,’ Ava said. ‘You had the chance to swim in a sea that’s actually warm, and you didn’t take it?’

‘I didn’t feel like it.’

‘Yeah, right.’

‘Ava,’ Mum said, ‘don’t tease her. Have you been for a swim?’

‘No, I’ve just been sunbathing.’

‘Well then,’ Mum said.

‘I didn’t realise it was compulsory,’ Ava said.

I understood what she was trying to do – to show that we didn’t have to talk about the dad stuff, and have some kind of big embarrassing heart-to-heart. We could just carry on as before, as if nothing really fundamental had changed.

But it had. I knew it had. Up close, I could see that her face was puffy where she’d been crying. I could feel the shock coming off her, and the woundedness.

She didn’t feel safe any more – how could she? She didn’t trust Mark, and she couldn’t really trust Mum in the same way as before, however much she might want to. And we’d all learned not to trust Sean long ago. But she would never want to talk about it – or at least, not to me.

The very worst of it was I had absolutely no idea how to console her, or to help. I couldn’t tell her what I’d seen. And I didn’t feel safe either.

Fourteen

Ava

If we had been at home I could have retreated to our room and kicked Ellie out; I would have had my books and all my stuff around me, and I could have got on with my revision and forgotten all about my family, at least for some of the time.

As it was, though, it was hard to escape. We had the sunshine and the beach and the three-course meals every night and the drinks in the hotel bar, and at the same time we were all stuck with each other and there was nothing I could do but wait it out.

The morning after the night of revelations, when Mum had come in to talk to me and I’d completely embarrassed myself by crying, I’d asked her whose idea it had been to break the news this way. On holiday! I’d think twice before I ever went on holiday with them again. It was Mark, of course. Left to herself, Mum would have had more common sense. She would have understood that I needed space, that I couldn’t be rushed into accepting him, let alone loving him. He must have steamrollered her into it, otherwise surely she would have at least tried to raise a few objections. But maybe she was just too preoccupied with the new baby to have any energy to spare.