I’d seen enough videos on YouTube not to be surprised. But what hit me was the smell. Ammonia that tore at the back of my throat, despite the overhead fans that shifted the thick air around the barn.

‘Don’t they get any bedding?’ Fiona said.

‘If the slurry system doesn’t allow for bedding, we don’t have to provide it,’ Kirsty said. ‘Slatted floors let the waste drop through. But that lot at the end get straw. They’re on a new system I’m trying, thanks to pressure from welfare people.’

Kirsty led us to the far side of the barn, to a pen that was bedded down with straw. ‘I’ve set it up exactly the same as at the abattoir. The same size, with straw, and with twenty six-month-old pigs.’

As we approached, the pigs roused themselves, grunting and pushing to the front of the enclosure. They had much more room than the others, presumably to replicate conditions in the abattoir.

‘They look hungry,’ Fiona said.

Kirsty nodded. ‘Pigs are always hungry. But these had a smaller supper than usual. I gave them the same as Anna said the pigs had on Sunday evening.’

‘Okay,’ I said. ‘It won’t hurt them, will it? Eating so much raw meat?’

‘No,’ Kirsty said. ‘They have stomachs of iron.’

‘Okay. You’re being admirably scientific about this.’

She hesitated then nodded. ‘I suppose it’s my way of coping with the situation.’

Kirsty opened up one of her bags and dumped the contents into a trough in front of the pigs. I winced. A sheep’s head, its wool removed. And some large chunks of leg. ‘I got the feet taken off,’ she said. ‘But left the head.’

I opened my bags and dumped the gruesome contents into the pigs’ trough. Mine contained a stomach and glistening intestines, which slid into the trough with a slap. Fiona winced and did the same with hers. The smell brought bile to my throat.

The pigs let out delighted grunts and shoved their snouts into the meat. They ripped into it, jostling against each other, pushing and shoving in their enthusiasm.

‘Shall we have a cup of tea and we can come back and check later?’ Kirsty said.

I looked at the pigs tucking in. They were approaching the problem with an extremely positive attitude, but it would surely take them a while to get through the bones, assuming they managed that, and I needed to get away from the smell. I nodded.

Kirsty took us back to the house and led us inside to a large kitchen. It was scruffy and homely and smelled of fresh bread, a relief after all the meat. A chunky pine table filled the centre of the room. Sheets of drawing paper were spread over it, along with some pencils and a box of charcoal.

I checked my watch: 1.03 a.m.