He turned away from her, faced back the way they’d come. She watched his shoulders rise and fall, the clouds of his breath. ‘I can’t … I need to think about this. I need to think what to do.’ He spun around again. ‘Don’t tell anyone else what you told me, all right? No one.’

‘Obviously.’

‘And don’t – repeat, do not – talk to anyone else about their case. Are you listening? Because if you do, I’ll arrest you, I mean it. I’ve got the grounds. Impersonating a police officer at the very least – I don’t have to tell you that’s a crime. Let alone anything to do with this other … Jesus Christ.’

He turned and walked away. He’d gone a handful of steps when he stopped again. For several seconds he said nothing. Then, ‘When it happened, were we together? You and me.’

‘Yes.’

‘Where was I?’

‘Cambridge. You’d gone to visit your sister for the weekend.’

‘And where was I when I came back?’

‘What do you mean?’

‘You were living with this, going through this “nightmare” and you didn’t tell me? How did you keep it from me, Robin? How could you? Something so massive. When we were so … close.’

‘Mum?’ In the dark, Lennie’s whisper seemed to float down from the top bunk. For a second Robin thought she’d imagined it. ‘Are you okay?’

‘Yeah,’ she whispered back. Then, because she wanted to acknowledge the olive branch, ‘Yes, I’m all right.’

‘What did he really want?’

When she’d come back in, she’d said he’d wanted to check a couple of things, ask her opinion on Rin’s state of mind. ‘He told me to stop interfering.’

‘But you’re not.’ Indignation.

‘I am. A bit. I can’t believe they haven’t got anywhere – I was trying to work out what they’re missing.’

‘Is that all?’

Oh, god: had she sneaked out somehow and listened? No, she’d checked behind them, she’d kept checking. And Lennie couldn’t have come close enough to hear without them hearing her. Robin’s stomach lurched – the idea of her daughter knowing. Even thinking about it in the same room as her now, as if the poison could seep out, get airborne.

‘When you came in, you seemed … upset.’

Robin flailed.

‘Was it a shock? Seeing him again?’

She hadn’t told her, had she, that she’d seen him before? ‘Yes. It has been. I saw him at the hospital, too – briefly. When I went to see Peter.’

‘You didn’t say.’

‘It didn’t seem important.’

‘Really?’ Lennie let the word hang.

It dawned on Robin what she was driving at. ‘Oh, Len, no. It’s not – no. That’s ancient history – like, pre-history. Cavemen. Dinosaurs.’ Quick, humour: the old deflector.

‘That’s not why – Adrian?’