At first, he didn’t react. Then slowly he looked down, registering the red bloom which was spreading outwards on his shirt like ink on blotting paper, part-hidden by his coat. He shuffled away from me, an expression of surprise on his face. He crashed into the corner of one of the pigs’ cages, but somehow managed to stay on his feet.

I watched transfixed as he dragged off his coat and dropped it on the floor. He pressed his hand flat against his stomach. Blood was everywhere. ‘What have you done?’ he gasped. ‘They’ll starve to death if I die.’ He lurched over to the far barn wall. Through the gloom, I could see that he was leaning over, tapping on a keypad. My heart pounded. He was typing in a code. Oh God. The carbon monoxide.

I clutched my knife, stood up, and tried to follow him, but the metal cuff was around my wrist. I yanked at it, but couldn’t get it off. I was chained to the wall.

Tony stopped typing on the keypad and there was a deep click, followed by a hissing and a whirring noise. Still clutching his stomach, he slipped through the barn door and slid it closed behind him.

I screamed. ‘Bex! Violet! Nina!’

Frantic voices from below me, muffled and hard to make out.

A faint ripping noise, and then Bex’s voice. ‘Can you hear me now? The vents are solid metal, and he’s sound-insulated them. I’ve ripped the cladding off, but there’s a piece of plastic between us still.’

‘I can hear you. I stabbed him. He’s badly injured. But he’s put the code in, Bex. I think it’s the carbon monoxide. I can hear it hissing.’

A pause. Then Bex: ‘Can you get out and get help?’

‘He chained me up. I can’t get away.’

More muffled voices.

Beside me was a large gas cylinder. A tube extended between it and a sealed hole in the floor. The cylinder was labelled ‘CO’. Carbon monoxide. The hissing was coming from it. Carbon monoxide was flowing from the cylinder and presumably into the sealed basement area.

I shouted, ‘Is the gas coming out? I can hear it.’

Muffled voices. ‘Yes. We’re trying to block the inlets but there are lots.’

‘I stabbed him,’ I said. ‘It’s my fault. He’s done it so that if he dies you don’t starve to death.’

My eyes had adjusted to the gloom. I peered down at my wrist. The cuff looked unbreakable. It was very clear he’d planned to put me here. But why? Was it so he could work out how to get rid of me in a way which looked like an accident? So nobody would come looking and find his little family.