We were done. We gave her our cards, sent her drifting out of the door with Houlihan, no backward glance.

Conway said, ‘Another one we can’t rule out.’

‘Yeah.’

‘Chris Harper’s ghost,’ Conway said, shaking her head, disgusted. ‘For fuck’s sake. And there’s McKenna upstairs, giving herself pats on the back because her and her shrine got rid of all that carry-on. I’d love to tell her, just to see her face.’

And, last of all, Holly.

Holly had changed her angle – for Conway or for Houlihan, no way to tell. She was all good little schoolgirl, straight back, hands folded in front of her. When she came in the door, she practically curtsied.

It occurred to me, a bit late, that I had no clue what Holly wanted off me.

‘Holly,’ I said. ‘You remember Detective Conway. We both really appreciate you bringing in that card.’ Solemn nod from Holly. ‘We’ve just got a few more questions to ask you.’

‘Course. No problem.’ She sat down, crossed her ankles. I swear her eyes had got bigger and bluer.

‘Can you tell us what you did yesterday evening?’

Same story as the other three, only smoother. No nudging needed here, no going back to correct herself. Holly reeled it off like she’d been rehearsing. Probably she had.

I said, ‘Have you ever put any secrets up on the board?’

‘No.’

‘Never?’

Quick spark, the impatient Holly I knew, through all that demure. ‘Secrets are secret. That’s the point. And no way is it totally anonymous, not if someone really wants to track you down. Half the cards up there, everyone knows who they are.’

Daddy’s daughter: watch your back, always. ‘So who do you think put up this card?’

Holly said, ‘You’ve narrowed it down to us and Joanne’s lot.’

‘Say we have. Who would you guess?’

She thought, or pretended to. ‘Well. It obviously wasn’t me or my friends, or I’d have told you already.’

‘You sure you’d know?’

Spark. ‘Yes, I’m sure. OK?’

‘Fair enough. Which of the others would you bet on?’

‘It’s not Joanne, because she’d have made a total incredible drama out of the whole thing – probably she’d have fainted in Assembly and you’d have had to go talk to her in her hospital bed, or whatever. And Orla’s way too stupid to think of this. So that leaves Gemma and Alison. If I have to guess . . .’

She was loosening, the longer we talked. Conway was staying well out, head down. I said, ‘Go for it.’