Faces in the white stairwell, craning over the circling banister-rails above and below us, open-mouthed. I called out, deep official voice, ‘Attention, please. Everyone go back to your common rooms. No one’s been hurt; everything’s fine. Go back to your common rooms immediately.’ Kept going till the faces pulled back, slowly, and were gone. Behind us McKenna was still shouting; the noise level was slowly going down, shrieks starting to crumble to sobs.

Conway was on her knees, up in Alison’s face. Sharp as a slap: ‘Alison. You look at me.’ Snapping her fingers, over and over, in front of Alison’s eyes: ‘Hey. Right here. Nowhere else.’

‘He’s there don’t let him please nononoooo—’

‘Alison. Focus. When I say, “Go,” you’re gonna hold your breath while I count to ten. Ready. Go.’

Alison cut herself off in mid-scream, with a sound like a burp. Almost made me start laughing. That was when I realised if I started, I might not stop. The scrapes down the back of my neck throbbed.

‘One. Two. Three. Four.’ Conway kept the beat ruthlessly steady, ignored the noise still bubbling down the corridor. Alison stared at her, lips clamped shut. ‘Five. Six—’ A swell of squealing in the common room, Alison’s eyes zigzagged— ‘Hey. Over here. Seven. Eight. Nine. Ten. Now breathe. Slowly.’

Alison’s mouth fell open. Her breath came shallow and loud, like she was half hypnotised, but the screaming was gone.

‘Nice,’ Conway said, easily. ‘Well done.’ Her eyes slid up over Alison’s shoulder, to me.

I did a double-take out of a cartoon. Me?

Flare of her eyes. Get a move on.

I was the one who’d made it work with Alison earlier. I had the best chance. The biggest interview of the case, or it could be if I didn’t fuck up.

‘Hey,’ I said, sliding down to sit cross-legged on the tiles. Glad of the excuse: my knees were still shaking. Conway slipped away sideways, into a corner behind Alison, tall and black and raggedy against the smooth white wall. ‘Feeling better?’

Alison nodded. She was red-eyed, more white-mousey than ever. Her legs stuck out at mad angles, like someone had dropped her from a height.

I gave her my big reassuring smile. ‘Good. You’re grand to talk, right? You don’t need the matron, more allergy medicine, anything like that?’

She shook her head. The chaos at the end of the corridor had ebbed to nothing; McKenna had the fourth-years under control at last. Any minute now, she was going to come looking for us.

‘Lovely,’ I said. ‘You said, in there, that you saw one of Selena Wynne’s gang do something. You were pointing at one of them. Which one?’

We braced and waited, me and Conway, to hear Julia.

Alison let out a little sigh. She said, ‘Holly.’