‘No,’ I say, shaking my head. ‘No, I haven’t.’

‘Well, hopefully you’ll never have to,’ she says, her eyes welling with tears. ‘My head was buzzing as I sat in that car and waited for Steve to return, my heart pounding at every little noise in case it was someone coming to find us. After about forty minutes I heard … oh my God, how do I even describe it? … I heard this terrible scraping sound. I looked in the rear-view mirror and saw Steve. He was … he was pulling the body along the side of the road and that was the noise I was hearing. I still have nightmares about that noise, even after all these years.’

I look down at the ground, remembering the sound of the glass as it sliced into Mark’s skin, and I know exactly how she feels. That sound haunted me as I lay on my bunk in that cell, praying for sleep to come and take it away.

‘Steve was well built,’ says Isobel, her voice snapping me out of my memory. ‘He played rugby, went to the gym, all that kind of thing, but Grace’s father was a big man alive let alone dead, and it took him the best part of an hour to get him into the boot of the car.’

‘Oh my God,’ I cry, putting my hand to my chest. ‘You had the body in the car.’

‘There was no other choice according to Steve,’ says Isobel impassively. ‘We had to get rid of it otherwise I was going to jail.’

‘Where did you take it?’ I ask.

She doesn’t reply, just stares straight ahead.

‘Isobel?’ I say impatiently. ‘Where did you take it?’

‘We didn’t have to go far, that’s all I’ll say,’ she whispers, her eyes clouding over.

‘Isobel,’ I say, my voice trembling. There’s something about her tone that is deeply unsettling. ‘Isobel, where did you bury the body? I need to know.’

She looks up at me then smiles a strange, resigned smile.

‘The lake,’ she says, gesturing to the outside with an outstretched arm. ‘We put rocks in his pockets, put him in the boat, then Steve waded out with it and tipped it over. The body went straight down.’

I sit there, frozen, trying to take in what she has just told me. The lake? There’s a dead body in the lake? I can’t take it in. My stomach convulses. I jump to my feet and retch on to the floor.

‘I … I don’t believe it,’ I say, wiping my mouth with the back of my hand. ‘It’s not possible. What about when the police came for Grace? Surely they would have drained the lake?’

‘That’s what I was dreading,’ says Isobel quietly. ‘Though, in her manic state, Grace told them she’d left the body in a graveyard. The police spent weeks searching all the nearest churchyards, ours included. My heart was in my mouth when they came to our door. I thought I’d been found out.’