‘Eleanor. Patrick’s wife.’

‘Yes.’

He looked wary at seeing me, his can rolling forgotten in the drawer of the machine. In the end, I decided just to be honest. After all, I wasn’t sure how much time we had. ‘Dr Holt – I need your help. It’s Suzi. Suzanne Matthews – I think she’s in trouble.’

Unsurprisingly, he didn’t believe me at first. ‘Eleanor – I know about you. You moved next door to her. You know that she . . . knew your husband.’

There wasn’t time for this. ‘Yes, they had an affair, but that’s not important now—’

He stepped forward, laying a hand on my arm. ‘Mrs Sullivan, please. I can help you. We have people here—’

‘You don’t understand. Suzi’s in danger. Her husband, Nick, I think he has her locked up! He said she’s at her mother’s, but she isn’t, and the music room’s locked and it’s never locked.’ It sounded crazy. How could I make him believe me?

He was frowning. ‘What?’

‘You’ve been in touch with her, haven’t you? I saw her emails on your computer. At first I didn’t know why you’d be involved with her – I even wondered if you were caught up in it.’

‘Caught up in what?’

‘The blackmail.’ I waved a hand; that didn’t matter now either. ‘But you weren’t, were you? You just cared for her. I didn’t understand why for ages – but then I looked you up.’

He went still.

‘Edward Holt, Jane Holt – they were your parents, weren’t they?’

‘Mrs Sullivan . . .’

‘Please! Please don’t send me away or call security or whatever you’re about to do. Suzi needs us. Yes, I meant her harm to begin with, I hated her, but it’s different now. You see? It’s changed. I’ve changed.’ Oh God, I wasn’t making sense. ‘Your mother – I know what she did. I understand why, OK? It was the same in my home.’ Jane Holt, a mild-mannered housewife who loved gardening, had stabbed her husband, Edward, to death one day in the middle of Sunday lunch. Her lawyers claimed she was the victim of decades of coercive control, but she’d gone to prison all the same, and died there a few years later.

He was shaking now. ‘How do you – you can’t—’

‘You get it, don’t you? How these things work, how someone can make you lose yourself, lose any faith you ever had in your own mind, your strength. We have to stop him, Dr Holt. Please come with me.’

I didn’t think it had worked – I thought he might insist we called the police, or just refuse to believe me – but after a moment I saw him nod.

‘Are you sure we’ll make it?’