And the journalist in me needs this. If Heather really did hurt Flora all those years ago, I owe her nothing now. I’d happily write a story about her. The irony doesn’t escape me that I would forgive Heather for murdering Clive and Deirdre Wilson because they mean nothing to me, but I’d throw her to the wolves over Flora. ‘I’m just taking this off,’ I say, folding my coat over the back of the chair. ‘It’s hot in here.’

Margot looks pointedly at it. ‘I’d say so in that thing.’ Then she seems to remember her manners, and blusters, ‘Not that it isn’t a nice coat …’

I’m not offended. I know my clothes aren’t to everyone’s taste. That’s why I like them.

Margot hands me one of the takeaway cups, which I accept with thanks. She gives the other to Heather. ‘I’ve got you herbal tea,’ she says to her daughter, smiling indulgently.

I place the cup under my nose. I can tell by the delicious aroma that it’s coffee and I’m thankful she hasn’t brought me some weak herbal crap. I need caffeine and I’m suddenly desperate for a cigarette.

I offer Margot my seat but she waves me away. ‘Oh, no, that’s fine. I need to make a call so I’ll go into the day room. I’ll leave you two to catch up.’

I watch her through the glass panel in the door as she stops to chat to the policeman on duty, although I can’t hear what they’re saying.

Now is my chance. I sit down and pretend to notice Heather’s ring for the first time. She’s holding her cup with her left hand; the right rests in her lap. ‘Oh, wow, I remember your family ring,’ I say, lifting up her right hand and pretending to admire it. ‘You used to always wear that when we were kids. Flora had one, too, didn’t she?’

I sound so fake, but I’m hoping Heather won’t notice.

She stretches her fingers. ‘Yes. Matching ones. We never took them off.’

‘Was Flora wearing hers the day she disappeared?’

Heather takes her hand away and uses it to cup her tea. She gives me a long look, her green cat’s eyes narrowed, and I hold my breath. Does she know what I suspect?

Eventually she says, ‘I thought so. But I found it afterwards. In her room.’ She holds up her right hand and wriggles her little finger. ‘I wear it now.’

I think back to the morning when I last saw Flora. I can’t remember if she was actually wearing it or not, despite what Margot said to the police. Maybe Heather’s not the psychopath I thought she was. And Margot would have noticed the extra ring, wouldn’t she? If it meant something. Heather must be telling the truth.