‘Did you put Nick’s body into his car?’ he asks. ‘Did you drive him down to Devon?’

‘No, I did not.’ I laugh, because the idea is so far-fetched. Marsh doesn’t crack a smile. ‘Look, what is this about? I don’t understand what I’m doing here.’

He nods, then leans back. ‘You’re here because I think you’re right, Ms Trelawney. I think it’s very likely that Nick did not kill himself, that he was murdered.’

‘What can you tell me about your relationship with Douglas Parr?’ Marsh asks.

The questions have been going on for over an hour now, and I’m feeling ill with exhaustion. Marsh and Grant look as fresh as they did when we began.

‘Civil.’

‘No conflict at all?’

‘Some, but it’s minor irritations. More like an annoying itch than pistols at dawn. Douglas has Lottie every other weekend. He adores her. It works because we both want it to, for her sake.’

‘I only ask because Cora Ritchie mentioned that he had some influence over you. She said that when he found out that her son was missing, he was straight in, telling you what to do, behaving in a hostile and threatening manner towards her and Tim.’

‘Cora is prone to exaggeration. Douglas has no influence over me. He has a strong personality, and she probably assumed I was affected by that. It isn’t true. I don’t care what he thinks any more. What has it got to do with Nick, anyway?’

Marsh raises his arms up and back and locks his hands behind his head, has a good stretch. He glances at Grant, who takes up the baton.

‘Grace,’ Grant says. ‘The police were called to the address you shared with Douglas on more than one occasion, when neighbours became concerned that a row had become violent. Once because they thought someone was going to get killed.’

She contemplates me, then sits forward, pushes the folder towards me. Paper-clipped to the top sheet is a picture of me, my mugshot in fact, taken that night in the police station. I look dull-eyed and very young. My hair is tied back and I’m wearing a white T-shirt. I remember that it had a slogan on the front, in sloping bright pink letters, that read, I’m Trouble. A WPC had commented, not unsympathetically, that it should have said I’m In Trouble.

I flip the folder shut and push it back with the tips of my fingers. ‘How long have you known?’

Grant ignores my question. I glance at Marsh, but his face is stony.

‘You tried to kill your boyfriend,’ he says. ‘You stuck a knife in him, rupturing his diaphragm. He lost four pints of blood and needed a transfusion and narrowly escaped death. That’s bound to make us wonder, don’t you think?’