We didn’t have the internet in prison, not in 2002, but I’d looked Rhonda up on a sort of newspaper microfiche thing, much like we had in the library at college. My heart had been racing with a combination of fear and curiosity. What had she done? Something really bad, to be in here. Or maybe she was innocent, like me. I found her after some while of clicking – WOMAN DROWNS CHILDREN. Well, that was short and to the point. Feeling sick, I read on. Rhonda, who’d been a professor of Black Literature at a university in San José, and was thirty-seven at the time it took place, in 1998, had one day driven her car into a lake, with her three children in the back. The children were aged one, five and seven. A dog-walker had seen the car go in and managed to pull Rhonda out in time, but not the kids. That poor man. What a thing to witness. As soon as Rhonda woke up in hospital, she was arrested, then a while later she was convicted of triple homicide and sentenced to death.

Her own children! I knew it happened sometimes, but I recoiled from it all the same, so when I saw her in the canteen I didn’t know how to act. I would have preferred to avoid her, like I would a girl at school who’d got too clingy, but there was nowhere to go in this place, no one else to talk to. I sat down, banging my tray nervously. Paola, who was mashing her potatoes in furrows, didn’t look up. Rhonda’s keen eyes took me in.

‘Paola, dear, might you leave us, if you’ve finished.’ And she did. Rhonda had been here a week and already ruled the place. ‘So. You looked me up.’

‘I – yes.’

‘I murdered my children.’

‘Did you? I mean – it wasn’t an accident?’

‘No. It wasn’t an accident. I just wasn’t supposed to be rescued.’

A murder-suicide. Very common when mothers killed their children, I knew. I had learned a lot about such things in prison. My lawyer had at one stage half-heartedly considered a defence where we blamed Abby for killing David and Madison, but the evidence all seemed to rule it out.

‘OK,’ I said cautiously. ‘And – you knew you were doing it?’

Rhonda shrugged. ‘I knew, but I couldn’t stop myself. You ever feel a darkness inside you, Casey, and you can’t help it rising up and taking you over?’

Had I ever felt that? Once, maybe. ‘I don’t know.’