‘Okay.’ I smile weakly as I pick up the glass of water that sits on the small table in front of me. My blood burns as it speeds around my veins like cars on a race track and I can’t sit still on the sofa as I lean forward, then back, before shuffling to the edge again, folding my hands in my lap.

But I am grateful for his kindness when he asks me if I’m okay to proceed. And I’m also grateful for the fact that at least someone is telling me they won’t lie to me even if they can’t give me everything I need.

The detective asks what I know about the incident and I tell him there’s absolutely nothing. He seems to accept this as he moves on to wider questions about Iona and my family. Did we see her often? How well did I get on with her? How about my sister? My mother? My father?

To start I tell him that during that summer I had always thought Iona was friendly and good fun, but that it was Bonnie who had formed a very close friendship with her. Though I don’t add it was closer than anyone else before and possibly even after.

I say that Mum was the one who instigated the dinner invites so I’d assumed she liked her, but what I don’t say is that at some point those invites must have dried up because in the last couple of weeks Iona stopped coming over. I realise I’d never given this any thought before now.

And Dad? My chest is tight as I tell Harwood that Iona and he got on well, that he made her laugh with his stories. I push my clammy hands beneath me, willing the fabric of the sofa to dry them out.

My omissions sit in hard lumps in my throat and it crosses my mind that one day I may have to tell a courtroom why I never said more.

But Harwood isn’t pressing me; instead he wants to know what other friendships Iona formed on the island. His question surprises me and I can’t work out where he is going with it when surely he must only be interested in my brother.

‘It was so long ago,’ I say, ‘and I was only eleven.’ It feels as if all my answers have been vague and I have a strange desire not to disappoint him.

‘I appreciate that, Ms Harvey,’ he says. ‘But can you think of anyone else she used to hang out with or talk about?’

‘Well, there was one girl,’ I say, the only person I ever saw her laughing with. ‘Tess Carlton.’