‘Tell you what; I’m not far from you. I’ll pop round. Be there in five.’ The line goes dead.

I look down at my phone. Maybe her coming here is for the best. I can suggest she doesn’t go home until she’s spoken to the police. Maybe she can book into a B & B for the night.

I watch from the window, waiting. Hoping she won’t think I’m over-reacting. In less than five minutes she pulls up, and I dash to open the front door.

‘Amelia? Whatever’s wrong?’ she says, locking her car, as she races up the path towards me. She pulls me into her arms, and I feel the fake baby bump, and I pull away. She clearly hasn’t broken the news to Neil yet. ‘You’ve worried me,’ she says. ‘Is everything OK?’

‘I’m so sorry.’ I lead the way into the house. ‘It’s just I really need to talk to you. It’s important.’

In the kitchen, I put the kettle on, and gesture for her to sit at the table. I take the seat opposite her, and twiddle a strand of my hair around my finger, arranging the words I want to say in my head so they make some sort of sense. ‘The thing is,’ I begin, ‘I found a book, well a kind of diary really, that my mum wrote before she died.’ I pause. ‘Rosamund, she saw you and Jackson together in the woods.’

‘What?’ Her eyes widen.

‘It was the night he and Lark disappeared. You were …’ I scramble for the right words, but she knows exactly what I’m trying to say.

‘That’s just not true. Look at me. Do I look the type of woman who would have sex in a wood?’ Her cheeks flush, and she avoids meeting my eye.

‘But why would she make it up, Rosamund?’ I narrow my eyes. ‘Why would she write it in her diary if it wasn’t true?’

There’s a beat. ‘OK, yes, yes—’

‘Christ!’ I lean back in my chair, cover my mouth with my hands. ‘Why the hell didn’t you say anything at the time?’ Why didn’t my mum?

She thrusts her head into her hands and begins to cry. ‘Jackson and I were having an affair – a fling really. It meant nothing.’

‘But you should have told the police you were one of the last people to see Jackson before he vanished.’

‘I couldn’t, OK.’ She looks up. ‘I couldn’t bear the thought of Neil finding out. I didn’t want to lose him. Is that why I’m here, Amelia? Are you going to rake it all up – ruin my marriage?’

I shake my head – no.

‘Then what’s so important that you needed to talk to me?’