I was bewildered, I hadn’t slept in days. I hadn’t washed and could smell the sour stink of my own body. I was losing track of what I had told them and what I had just thought in my head, or what they said I’d told them when I hadn’t. They just kept questioning me, relentless. But Casey, you said before the door was closed when you came home. Did I? No, I was sure it had been ajar when I went back to it. I remembered my spike of fear that I had left it open, that Madison might have run out on the road. She had opened the door once or twice before – maybe she’d done it this time too, and that meant anyone could have come in, in theory.

The male cop slapped the table lightly. ‘We’ll certainly look into this José guy. See if he has a record in his own country. Maybe send him back there.’ He winked at me. It seems insane, but it actually happened. This man who was questioning me over a multiple murder, he winked at me over the subject of deportation. I wondered had it ever crossed his mind that I was an immigrant too.

I was lying on my bunk later that day when the door buzzed. I had found I was able to spend hours this way, looking at the damp stains on the ceiling, just breathing in and out. If I thought only about that, my breath and the ceiling, the sagging mattress beneath me, I could manage not to think about the terrible situation I was in, Madison, Abby and David dead, and me accused of their murders.

At the sound of the buzzer I jumped up, almost hitting my head on the low ceiling. It was the female guard I hated, broad about the hips and fond of hitting out with a baton, which was what they called a truncheon. I’d always thought that was a funny word, but the reality was not funny at all, when it jabbed you in the soft space under the ribs, leaving hollows that ached for days.

‘What?’ I said.

‘Detectives want to see you.’ I blinked and she barked at me. ‘I don’t have all day! Jesus, who do you think you are, Paris Hilton?’

I had only the haziest idea who Paris Hilton was, but I scrambled down the rusty ladder. I was in the orange jumpsuit we all wore, deeply unflattering to my skin. Except for that brief trip to court, I hadn’t seen the sky in what I calculated was three weeks.

She grabbed my arm above the elbow, which I knew would leave deep finger-marks, and I tried to go floppy and unresisting. Be like water. Water could not be marked. She dragged me along to the interview room, where I’d been a constant presence for weeks now.