I could hear Doug and Oliver talking in the kitchen. I had only seconds to decide. ‘Shush,’ I said. ‘Shush, Rose. Stop and let me think.’ She watched me anxiously, her eyes never leaving my face. ‘Rose,’ I said at last, ‘you must never tell another soul about this. No one, not ever. Does Oliver know?’

She shook her head. ‘You’re the only person I’ve told.’

‘OK. Good.’ I could hear the others, about to come back in. ‘She jumped, Rose,’ I said. ‘OK? It wasn’t your fault.’

She nodded, her frightened eyes wide. ‘Yes.’

‘It’ll be our secret, no one ever has to find out.’

‘You’ll never tell anyone? Do you promise?’

‘I promise.’

It’s a detail I’ve always carefully omitted over the years, when I’ve told myself the story of how Hannah came into our lives. Because it casts a rather different light on things, doesn’t it? I wanted Lana for myself, you see. I knew it from the moment Rose appeared on my doorstep that night. If Doug had known the truth behind Nadia’s death, he would have gone to the police, I have no doubt about that. So when I promised Rose I would keep her secret, it was myself I was thinking of, deep down. I can’t pretend otherwise any more, no matter how hard I’ve tried to wipe it from my memory. It was so I could keep Lana for myself. Does that make me as bad as Rose? Yes, actually, I rather think it does.

And so, of course, I did keep the promise I made to Rose that night. I didn’t tell another soul. In fact, neither of us spoke of it again, not even the day Hannah overheard us talking in the kitchen. All she heard was Rose saying she’d been the last person to see Nadia alive, that everyone would think she’d killed her, and Hannah, not wanting to believe her mother would abandon her by choice, put two and two together herself. So for years I kept Rose’s secret – until, that is, the day that Emily found me.