‘Okay. I hate to diagnose on the phone, but it sounds like she’s de-lusional.’

‘You think so? Holy shit.’

Simon chuckles. In the tiny speaker it sounds like he’s gargling tar. ‘Okay. I’m re-membering you now, McEvoy.’

‘What can I do?’

‘Don’t shatter her illusions too harshly. You could do irreparable damage. Play along for the time being, until you can get professional help.’

‘That could be tricky.’

‘Tricky how?’

‘I think Sofia could turn violent. She’s been hurt before.’

I hear Moriarty drag deep on his cigar. ‘Christ, this is so unprofessional. Look, Dan, if you care for this woman, get her into treatment. Use some pretext or other, say it’s marriage counselling.’

‘Marriage counselling. Nice one.’

I am about to fold Macey Barrett’s phone when Dr Moriarty asks a question.

‘And what about you, Daniel? How are you?’

‘Cracked knuckle, maybe.’

‘Mentally, smartarse.’

How am I? There’s a question. I’m carrying around my best friend in my head. I’m obsessing about my hairline and I am giving serious consideration to entering a relationship under an assumed name.

‘Yeah, I’m fine, Simon. Really.’

I can hear Moriarty’s pen clicking on the other side of the Atlantic. ‘You’re lying to me, Daniel.’

‘You sure?’

‘Yes, I’m sure. It’s all Doc-Moriarty-arsehole. Then suddenly it’s Simon. You’re trying to gain my trust by humanising yourself. Textbook stuff.’

‘I am human, Simon.’

Another chuckle from Ireland. ‘Not to me. To me you’re nothing more than a few stripes on a sleeve.’

I realise that I like this guy and that it would be good to have a beer and not discuss my various hang-ups, fixations and neuroses.

‘I suppose I’m trans-parent to you, Doc.’

‘Absolutely.’

I take a deep breath, realising that there is no way to say what I am about to say without sounding a little section eight. ‘Okay, Doc. I have this friend.’

‘Really? You have this friend who can’t get an erection and could I make the prescription out in your name?’

‘No. Not like that. I have this real friend whose personality lives in my brain.’ Shit, there, I’ve said it.

‘You’re just having conversations in your head, playing devil’s advocate with yourself; everyone does it.’

‘No, it’s more than that. He’s a real presence. He doesn’t follow the rules.’

‘You have rules for your imaginary friends, Dan?’

‘Hey, I’m pretty sure that you’re not supposed to mock your patients.’

‘When you send me a cheque, you can be my patient.’

There is no point trying to outsmart this guy; he does it for a living. So I forge ahead.