‘Yeah,’ I said. The way she said it – scary fuckers – like she knew, like she’d been there: that was what helped, more than the reassurance. ‘OK.’

‘Good.’ Conway clapped me on the shoulder. Awkward as a boy, but her hand felt strong and steady. ‘Fair play to you.’

I said, ‘It’s not enough. We’ve got enough to arrest Rebecca, but the DPP won’t charge her on this. If she doesn’t confess—’

Conway was shaking her head. ‘Not even enough for an arrest. If she was some skanger kid, then yeah, sure, haul her in and see how far we get. But a girl from Kilda’s? We arrest her, we have to be able to charge her. No ifs. Otherwise we’re fucked. O’Kelly’s gonna pop a vein, McKenna’s gonna pop a vein, the Commissioner’s phone’s gonna be ringing off the hook, the media’ll scream cover-up, and we’ll be sharing a desk in Records till we retire.’ That bitter curl to her mouth. ‘Unless you’ve got friends in high places.’

‘That was the best I’d got.’ I nodded upwards, towards the art room. ‘And I’d say that’s well scuppered now.’

That got part of a laugh. ‘Then we need more on Rebecca. And we need it fast. We have to get her in custody tonight, or we’re fucked. Julia and Holly, they’re both smart enough to figure out where this is going – if they don’t already know.’

I said, ‘Holly knows.’

‘Yeah. We leave the four of them together overnight, they’ll talk. We’ll come back tomorrow morning and they’ll have their stories all nice and matched up, butter won’t melt, they’ll have worked out exactly where to lie and where to keep their mouths shut. Not a chance in hell we’ll crack them.’

I said, ‘We won’t crack Holly now. She’s given us everything she’s going to.’

Conway was shaking her head again. ‘Forget her. And Selena. We need Julia.’

I remembered what she had said earlier: This year Julia’s watching us like we’re actual people, you and me. And then: I can’t work out if that’s gonna be a good thing or a bad one.

‘Mackey and Holly,’ I said. ‘Leave them where they are, yeah?’

‘Yeah. We might need them again, and we don’t want them running around getting in our way. If they don’t like it—’

This time we both froze. Only a few yards behind us, round the front of the boarders’ wing, someone’s foot had slid on pebbles.

Conway’s eyes met mine. She mouthed Mackey.

We moved fast and silent, swung round the corner together. The carriage sweep was wide and white, empty. The grass was bare. In the dark crack of the door, nothing moved.