‘Our lab analysed the substance you brought in,’ he said. ‘It is indeed heroin. As you told us. We also had the plastic container fingerprinted. Can you guess what I’m going to say?’

‘That Charlie’s prints weren’t on it?’

‘Correct. Actually, we don’t have Charlotte Summers’ prints on record. But we do have yours.’

I swallowed. A dim memory surfaced, of a cop in a different station pressing my fingers into a pad of ink.

‘And there was only one set of prints on the bag, Andrew,’ Moseley said. ‘Yours.’

‘I’m not denying that I touched it. You know I did. I handed it to you! But Charlie must have worn gloves.’

Moseley stared at me. ‘Here’s what I think happened. You and Karen Jameson had a disagreement over the money she owed you. Or perhaps it was a lovers’ quarrel. Karen was jealous of your new, younger girlfriend. You murdered her, injected her with a dose of nearly pure heroin while she slept beside you, then panicked and came up with this crazy story about your girlfriend doing it.’

‘Pretty nasty,’ Jones said. ‘Killing one girlfriend and trying to frame the other for it.’

‘This is mad,’ I said. ‘It was Charlie. I can’t believe you haven’t talked to her. She’s still out there. Listen, if you don’t get her in custody, I have no idea what she’ll do. I’m worried she’s going to do something to Sasha.’

Moseley raised an eyebrow. ‘Sasha? Who’s that?’

I didn’t like his expression. ‘A friend.’

The two detectives exchanged a glance. ‘Quite the Casanova, aren’t you? It’s always the quiet ones.’

I could sense Jones sizing me up, a slight curl to her lip. It was dawning on me that maybe I should ask for a solicitor. It would have to be the duty solicitor as I didn’t have enough money to hire my own. But would that seem like an admission of guilt. This whole thing seemed so ludicrous that I couldn’t believe the detectives weren’t going to break into laughter at any moment, point at me and say, ‘Gotcha!’

‘If I was guilty, why the hell would I come here and bring you the heroin? As far as I know you weren’t even treating Karen’s death as suspicious until yesterday.’

Moseley leaned back and the look he gave me chilled my blood. ‘This isn’t the first time you’ve done this, is it, Andrew?’

My words could barely squeeze past the lump in my throat. ‘What are you talking about?’

‘Come on. Don’t act the innocent.’ He actually said those words. ‘We had a look at your record.’

The door opened and another plain-clothed policeman stuck his head in, gesturing to Moseley.

‘Excuse me,’ he said, pausing the interview, and both he and Jones left the room, leaving me alone in a horrified daze.