Conway, in the corner of my eye, giving me a sliver of a nod. We were back on safe ground. If Joanne repeated that speech to her counsel someday, it said witness, loud and clear. But if it worked, if she admitted to being at the scene, she crossed over the line to suspect, no leeway left.

‘But I’m also sure, Joanne, I’m just as sure that you saw something, or heard something. You know who killed Chris Harper.’ I let my voice rise. ‘Time to stop hiding it. You heard what Detective Conway said, earlier. It’s time to tell us – before we find out on our own, or someone else does. Now.’

Joanne wailed, ‘But I don’t! Honest to God, I swear, I didn’t go out that night! I hadn’t been out in weeks.’

‘You’re trying to tell me you didn’t have anyone to meet? Almost six months after Chris dumped you, you were still single?’

‘Not still – I went out with Oisín O’Donovan for a while, you can ask anyone, but I dumped him weeks before Chris happened! Ask him. I wasn’t out that night. I don’t know anything. I swear!’

Huge-eyed, hand-wringing, all the trimmings: the way she’d learnt that innocent looked, off the telly or wherever. Truth or lie, it would look exactly the same.

Another minute and she’d be scrunching up her face, trying to cry. Conway’s eye said Kill it.

I eased back, on the soft intimate squash of Gemma’s bed. Joanne drew a long shaky breath, snatched a sideways glance at me to make sure I’d caught it.

‘OK,’ I said. ‘OK, Joanne. Thank you.’

Joanne and her shorts headed back to the common room. Her arse watched us watching her, same as Julia’s, only not the same at all.

‘That’s one pissed-off little geebag,’ Conway said, tinge of enjoyment. She was leaning a shoulder against the wall of the corridor, hands in her pockets. ‘She can spin it however she wants: she was well fucked off with Chris Harper.’

‘Fucked off enough to kill him?’

‘Sure. She’d’ve loved to. But . . .’

Silence. Neither of us wanted to say it.

‘If she could’ve pushed a button,’ I said. ‘Stuck a pin in a voodoo doll. Then yeah.’

‘Yeah. Like that.’ Finger-snap. ‘But heading out there in the dark, smacking him in the head with a hoe . . . I can’t see Joanne taking that kind of risk. She wouldn’t even go after Selena without dragging Gemma along. Very careful of herself, our Joanne. And she doesn’t step outside her comfort zone. Fuck.’

‘The card could still be her.’ I heard the silver-lining note in my voice, waited for another Pollyanna jab. Didn’t get it.

‘If it is, she’s trying to steer us towards Selena. Now there’s revenge. You rob my fella, I’ll frame you for murder.’