Ben. It was him to an absolute tee. A way of using technology to get what he wanted, and proving how clever he was into the bargain.

The File Manager showed one audio file, just fourteen seconds long.

Two voices, one of them mine.

‘You know, we could be a team, me and you.’

‘A team?’

‘We need to work together to stop this. To bring Ben to his senses.’

‘Makes it sound like it’s us versus him.’

‘Well Beth, I hate to be brutal about this. But that’s the way it –’

And then it cut out. Almost as if it had been a test. Or a mistake.

I remembered the conversation: it had been at the park with Beth on Thursday morning. Ben had been eavesdropping on us the whole time. The recording meant he knew Beth and I were working together. He knew I’d ignored his various warnings to stay away from her.

It also meant Beth was in even more danger from him.

I deleted the SysAdminTrack app and sat back in my seat. The bruises on my face had started a slow, constant throb, a steady pain that flared higher whenever I touched a fingertip to my jaw or eye socket. I stared out of the window for a few minutes before remembering the call I’d rejected earlier, at Ruth Delaney’s house, before she’d gone crazy with the knife. The number was stored in Received Calls, probably an automated message on how to make a PPI claim. My finger hovered over the delete option.

I called it instead.

A male voice answered.

‘Hi Joe, how are you doing?’

‘Uh, OK thanks. Who’s this?’

‘Mark. Mark Ruddington.’ From the background noise it sounded like he was driving. ‘You messaged me on Facebook, remember?’

‘Oh – sorry, of course. Thanks for getting back to me.’

‘So you’re Melissa’s other half?’

‘Yes.’

‘Cool, cool. How’s she doing? She all right?’

‘She’s good, thanks.’

‘Cool. This is so weird, you know? She was like my first proper girlfriend at school. And now here you are, her husband, messaging me on the Book of Face twenty years later, and it’s like, wow, you know? One of those connections you never expect to make.’

‘A blast from the past.’

‘Exactly. A blast from the past.’

I had a feeling this might go on for some time before it got to the point.

‘So I was writing this speech for our tenth wedding anniversary party,’ I said, ‘and I thought I’d try to get some funny stories from her schooldays. You mentioned something in a Facebook post a while back that sounded interesting. About a production of Macbeth in your GCSE year?’

‘Oh. That.’ The tone of his voice changed.

‘The after-show party?’

He paused, and I thought I heard him take a deep breath.

‘Melissa hasn’t told you about that, then?’