‘This. Having this conversation...’ Her voice trailed off and she made a small, helpless gesture. ‘I never have. People don’t know. I didn’t want you to know.’

Her eyes drifted down to where her hands were clenched in her lap.

‘But you knew anyway,’ she whispered.

‘Knew what?’

She was shaking her head. ‘Remember that first day we went diving?’

His eyes narrowed. ‘I remember that I was irrational and unfair.’

‘You told me that I didn’t follow, though, and you were right. Maybe not about that dive. But about me. The one time it mattered I didn’t follow through. I did the opposite, I gave up. Even though he had nobody else I left him. I left him to die.’

Chase stared at her in silence. His heart felt as if it were trying to break through the bars of his ribcage. Whatever he had been expecting her to say, it wasn’t that.

‘Left who?’ he said finally.

‘My father.’ She sounded breathless, as if she’d been running and maybe she had. Fleeing from the past, the memories, the pain. It was so hard to keep out of reach. Harder still to turn and face them. He stared at her in silence, remembering how it had felt telling her about Frida. But this was her story, he could only prompt her to tell it.

‘How did he die?’

‘He got hypothermia. He’d been trying to get into his flat, but he was always losing his key and nobody was there to let him in. The police thought he decided to sleep in the porch.’

She was shaking now as if she was cold too.

‘Why didn’t he go to a friend’s house or a hotel?’

‘He didn’t have any friends. He didn’t have anyone. He had people he drank with, but they were like him.’

‘Like him?’

‘He was an alcoholic. I don’t know exactly when it started but by the time I came along it had gone from him liking a drink to needing one. And then another, and another.’

The exhaustion in her voice came from another time.

‘That must have been hard.’

She bit her lip. ‘It was. Particularly for my mum. She loved him so much.’

‘How did they meet?’

‘They worked at the same university. He was a professor of political science but he also wrote columns in various newspapers. He had this beautiful voice. My mum used to call him the “snake charmer” because he could get politicians to say things that nobody else could. When he wasn’t drinking he could be sweet and funny but alcohol made him nasty, and he kept losing jobs. They got divorced and a couple of years later my mum got remarried to this really nice man called Adam, and then Holly and Ed were born.’

Which explained why the twins were so different from her, he thought, gazing over at her small, pale face.

‘Adam’s lovely.’ Some of the tension in her voice eased a fraction. ‘He’s so solid and kind. I think him being like that was one of the reasons why I decided to go and live with my dad. Because I knew Adam would look after everyone. And my dad needed looking after.’

‘How old were you?’ he said quietly.

‘Thirteen, nearly fourteen. It wasn’t that I didn’t see him. I did. I saw him every weekend but I hated leaving him, and it didn’t feel fair for him to be alone.’ There was a shake in her voice now. ‘And I thought, I actually believed that I understood him better. That I could help him. But it was so hard.’

As she pressed her hand against her mouth, his throat felt so tight it ached even to breathe.

‘There was never any food. He kept forgetting to buy it, so I got him to put money aside but when he needed alcohol he’d just take it. Sometimes he’d fall over and hurt himself. One time, he collapsed and he got taken to hospital but he discharged himself. Another time he got mugged and he came home covered in blood, but I didn’t want to tell anyone because it felt like I’d be betraying him.’

Chase felt his heart squeeze tight. He understood what it was like to feel both helpless and responsible, but he had been an adult. At thirteen, Jemima was little more than a child.

‘Had he been drinking that night?’ he said gently.