‘I do actually wash the glasses before I put them away,’ I snipe, moving to sit next to him on the tiny sofa. ‘Listen, I need your help with something.’

‘Oh yeah?’ He leans forward and kisses my neck.

‘Si, I’m serious, I need you to listen to something.’ Pushing him away, I pull the dictaphone from my pocket. ‘Just listen to this, OK?’

Si exhales loudly and then I hear the voice again, over the crackling of the recorder. I really should invest in a digital one, though somehow it would feel disloyal to Maureen to get rid of the one she gave me. In the eight months since we’ve got to know each other properly, she’s become as much a mother figure as a friend.

Isobel, I am watching you. No police, or I will kill you too.

‘What the hell’s that?’ Si shifts slightly away from me.

‘It’s him,’ I say. There is a satisfaction in my voice and I stare intensely at him for a moment, challenging him to contradict me this time.

‘Who?’ He looks concerned.

‘It’s the man I was telling you about. The one from the Heath, who sent me the shoes! The brick, I …’ There is more excitement in my voice than fear and Si blinks.

‘What the hell? Start at the beginning. He’s called you?’

‘Yes! I need to ask you something. You studied languages …’ Si looks up, as if he had misheard the question.

‘Listen to this, in the background. If you turn the volume up you can hear talking … Is it anything you recognise?’

Noting the desperation in my face, he reluctantly closes his eyes and listens. The recording is grainy but under the fuzz there are clearly men’s voices in the background, though the whole thing feels distorted.

‘God, I don’t know, I can hardly bloody hear them …’

Turning up the machine to full volume I press Play again and watch his face intently.

‘Yeah I think he’s used one of those voice-masking apps. It’s all a bit slurry.’

Si shakes his head. ‘I don’t know what language it is they’re speaking but it’s nothing I understand.’ There’s a pause and then he says, ‘Is …’ His voice is cautious. ‘I’m really worried about you.’

Without saying another word he leans forward and pulls me gently against his chest. When he releases me a few moments later, he doesn’t try to kiss me. Rather, he says, ‘I think you should call Oscar.’

Knowing how Si feels about Oscar, I know what it must take for him to mutter these words.

I nod. ‘Yeah, I’ll call him in the morning,’ I say, knowing full well that I won’t.

Si is pulling on his trousers the following day, ready to leave for court, when it strikes me.

‘Hey, what about that old professor of yours? What’s his name … something Mansfield?’