Selena’s phone to Chris’s: Can you meet tonight? 1 in the cypress clearing?

4.00 p.m. – he must have checked his messages after school – Chris’s phone to Selena’s: OK.

Whoever had set up that meeting had killed Chris Harper. We had room for a crack of doubt – interception, coincidence. No more than that.

‘Love to know who he thinks he’s meeting,’ Conway said.

‘Yeah. Not Mystery Girl’s usual day, not her usual MO – this time she asks for an answer.’

‘It’s not Selena. “Cypress clearing”, Selena wouldn’t’ve said that. That was their spot. “Same time same place,” she’d’ve said.’

Selena was out, again. I said, ‘But Chris could’ve thought it was her.’

‘Could be what Mystery Girl wanted him to think. By now, she’s planning. She breaks the routine to get Chris wondering, make sure he shows up. Takes the risk of having him text her back – maybe she does nick the phone outright, this time. She knows no one’s gonna be using it from now on.’

Conway’s voice was level and low, rough-edged with fatigue. Small eddies of air nosed around it, curious, carried it away down the corridor.

‘Maybe Joanne’s twisting her arm; maybe she’s doing it off her own bat, for whatever reason. That night she sneaks out early, takes the hoe out of the shed – she’s wearing gloves, so no prints. She heads for the grove, hides in among the trees till Chris arrives. When he’s mooning around the clearing waiting for his twue wuv to show up, our girl hits him with the hoe. He goes down.’

The lazy drone of bees, this morning, long ago. Seed-heads round my ankles, smell of hyacinths. Sunlight.

‘She waits till she’s sure. Then she wipes down the hoe, puts it back where she got it. She takes Chris’s secret phone off his body and gets rid of it. Gets rid of Selena’s, too. Maybe she does it that night, goes over the wall and ditches them in a bin; maybe she hides them somewhere in the school till the fuss dies down. Now there’s nothing to link her or her mates to the crime – except maybe Joanne, and Joanne’s got enough cop to keep her mouth shut. Our girl goes back inside. Goes to bed. Waits for the morning. Gets ready to squeal and cry.’

I said, ‘Fifteen years old. You think any of them would have that kind of nerve? The murder, OK. But the wait? This whole last year?’

Conway said, ‘She did it for her friend. One way or another. For her friend’s sake. That’s got power. You do that, you’re Joan of Arc. You’ve gone through fire; nothing’s gonna break you.’

Shiver building dark in my spine, the way it does when power comes near. That beat of pain again, deep in the palms of my hands.