Edie’s gaze falls on Kira. ‘Kira Simmons! My gosh, I haven’t seen you since …’

‘I left school three years ago,’ Kira says. ‘I’m doing photography up there.’ She gestures towards her college.

‘Yes, of course. Your GCSE project was about sport, wasn’t it? BMXers and skateboarders?’

‘Sort of. It was about perseverance.’

‘That’s right. Lots of images of scraped knees and jubilant air punches if I remember correctly.’

Kira slips her hand through the crook of my elbow. She tugs me, ever so slightly, away from Edie Christian. At the same time the two boys I’ve been watching disappear into a crowd of people crossing the road and the band around my chest loosens.

‘I didn’t realize you two knew each other,’ Miss Christian says, looking pointedly at Kira’s hand on my arm.

‘Kira lives with us. She’s my son Jake’s girlfriend.’

‘I remember Jake. He was a hard worker. Oh!’ She looks back towards the group of school kids on the other side of the road. ‘I’d better be off. Good to run into you, Mrs Wilkinson. I know you’re probably in touch with Mr Edwards but if there’s anything I can do to help, then do let me know.’

‘Miss Christian!’ I call as she starts back up the street.

‘Yes?’ She turns back.

‘You ran into my husband, Mark, near Gloucester Road.’

‘Did I?’ Her expression changes. It’s the same worried look I saw in the photo. ‘Yes, outside the doctor’s. I remember.’

‘How was he?’

‘Um.’ She looks confused. ‘He seemed well. I’m so sorry, Mrs Wilkinson. I’m really going to have to go. Rosie isn’t legally allowed to take charge of that many kids on her own and …’ She raises a hand in goodbye, then speeds across the road just as the green man turns red.

‘What was that about?’ Kira asks.

‘I don’t know,’ I say. ‘What was she like – as a teacher, I mean?’

I’m interrupted by the muffled sound of my mobile phone ringing inside my bag. DS Forbes said it could take weeks to follow the new line of inquiry. If the call is from him it can only be bad news.

A name flashes on the screen. I press ‘end call’ without picking up.

Tuesday 25th November 2014

ICE9: We need to be careful. I thought I saw your mum at the window last night.

Jackdaw44: Probably wondering where Dad was.

ICE9: Where is your dad?

Jackdaw44: At a conference. If ‘conference’ is another word for fucking someone else.

ICE9: Do you really think he’s cheating on your mum?

Jackdaw44: Hello?!

ICE9: Yeah. I know, but maybe what you saw was a one-off.

Jackdaw44: And you think I’m the naive one.

ICE9: I never said that.

Jackdaw44: You think I’m too young for you.

ICE9: Did I say that?

Jackdaw44: No, but I know you’re thinking it.