Early Saturday morning I am called back into the interview suite to see Detective Harwood and this time he seems more agitated. ‘Your brother is adamant he killed Ms Byrnes,’ he tells me. Like me, he is grappling for the truth but can’t quite get to it, and he’s feeling the pressure.

Danny has now been held for nearly forty-eight hours and my limited online research tells me they only have ninety-six in which to question him. This means by Monday morning they need to either charge my brother or let him go.

‘He says he arranged to meet her at a point on the island by the edge of a cliff.’ Harwood passes a map of Evergreen to me, prodding his pen at a spot. I pull it closer and peer at the mark his pen has left, taking a deep breath and then passing it back to him.

‘I know exactly where that cliff is.’

‘Why do you think he might have arranged to meet her there?’

‘I can’t think why,’ I say, refusing to acknowledge it’s the exact spot I used to meet Jill. Our secret place. The only reason I can think of is that Danny didn’t want to be seen.

But it is also, of course, the spot where I saw my dad and Iona, and an unwanted image of them flashes in my head. Even when I blink it doesn’t disappear. Dad was so adamant yesterday that he didn’t have an affair. And yet I saw him – I’m sure I did. I see his cap vividly and it is this I keep coming back to.

‘Daniel says this is where he and Ms Byrnes fought and then he shoved her. He saw Iona fall back over the edge.’ He prods again at the map; this time his pen marks a spot on the thin stretch of beach below.

‘But what your brother describes is inconsistent with what we know. And where she was found. This area, here.’ He points to the spot just outside my house where Iona’s body was dug up. This time he uses his finger to circle around it. ‘Who had access to it?’

‘Well – everyone,’ I say. ‘It’s on the edge of the woods. Anyone could go there if they wanted: islanders, visitors …’ I trail off.

‘So day visitors would pass by the end of your back garden?’

‘No, I said they could. There was access to it. But they rarely did, and usually it would have been because they’d got lost. The people that came to the house that way were friends, though most of the islanders used the gate. I think it seemed like a more polite entrance. Mum preferred it.’

Harwood nods, though I sense his impatience. ‘So, who in particular do you recall coming to the house via the woods?’

‘Annie Webb and Susan Carlton usually, but they lived in that direction.’