‘So you would, then?’

‘No.’ She regains her composure. ‘That’s not what I said. I’d use my professional judgement to work out what to do, and what to advise you.’

‘You’d tell me to go to the police?’

‘Well, yes. I’d be more likely to advise you to go to the police than do it myself but if I did report the crime to the police it wouldn’t be without your knowledge. And I would discuss it with my supervisor first.’

I weigh up my options. I could keep quiet and get rid of the knife. I could talk to Liz about it. Yes, that’s what I should do. I should tell Liz. But if I have committed a crime that would make her an accomplice. And what could she do, anyway, other than tell me to go to the police, tell Mark or keep quiet about it – all possibilities I’ve already considered myself.

If I tell Sonia, I get a psychologist’s insight into what happened. And if she can’t help me maybe I should go to the police? The only way I’ll find out whose blood is on the knife is for them to check it for DNA and ask the car-park company to look at the CCTV. But what if it reveals that I stabbed someone? I kicked a cyclist after I came round from my second fugue. What if I’m capable of worse? If I killed someone I’d be jailed for murder.

‘Claire.’ Sonia moves the box of tissues away from me. ‘Claire, it’s okay.’

There is a pile of torn tissues on the floor in front of me. I don’t remember reaching for the box. How can I have shredded that many and not noticed?

‘Whatever happened –’ Sonia crouches on the floor beside me, her eyes soft and non-judgemental – ‘it has obviously really upset you. Have you spoken to anyone about it? A member of your family, or a friend?’

I shake my head.

‘You said you might have committed a crime, not that you did,’ she says softly. ‘There’s a difference. Tell me what happened.’

‘I can’t.’ I shake my head. ‘I can’t remember.’

‘Then what makes you think that’s a possibility?’

‘There was a knife –’ the word catches in my throat – ‘on the floor next to me in the car-park toilet. It was covered in blood.’

She nods, gently urging me to continue.

‘It was one of my steak knives. I checked the drawer when I got home. There are supposed to be six, but one is missing.’

‘I see.’ Her expression remains impassive. ‘And when was the last time you counted the knives? When did you last check that there were six?’

‘I don’t think I ever have. I bought them years ago and put them in the drawer. I’ve never bothered counting them because we only ever needed five.’