When the kicking had stopped, the operator put his gun down and began to secure the straps of a winch. A moment later, the dead mare was hoisted off the floor on two chains, its back legs high in the air, its head hanging downwards, swinging loose. A spiral of blood squirted on to the tiles.

‘My God, it’s like watching a snuff movie.’ DI Hitchens stood behind Cooper, watching over his shoulder. ‘Does this happen every day?’

‘Well, every week, at least,’ said Cooper.

They were watching a film that seemed to have been made secretly by an animal rights group. Somehow, they had managed to get a camera into the slaughterhouse in Yorkshire on the day they killed horses. The quality of the picture was poor, and the sound even worse. Also, the film had been shot from an odd angle. Cooper guessed at a small, hidden camera of some kind. Maybe even a mobile phone, though most people were wise to that now. It would need to have been left on a shelf or ledge high in a corner of the killing room, to get that angle.

‘Where is this place?’ asked Hitchens.

‘C.J. Hawley and Sons. It’s somewhere in West Yorkshire. North of Sheffield, anyway. I rang them a few minutes ago. They didn’t used to take horses for slaughter, but there are only three other abattoirs in the equine business, and all of those are located further south. So Hawleys took up the spare demand. They slaughter horses one day a week now.’

‘It looks as though the animal rights people were on to them pretty quick.’

‘I suppose it looks bad when you watch like this,’ said Cooper. ‘It makes the whole thing look seedy and surreptitious. But the abattoir isn’t doing anything illegal. They’re inspected and supervised, just like any other operation.’

‘So they’re clean?’

‘The protestors would probably argue a moral case.’

‘Morality is beyond our remit,’ said Hitchens.

‘Hold on, sir. There’s a bit here I want to listen to.’

The dead horse was disappearing through a doorway, being moved on some kind of overhead gantry. The carcass swung awkwardly as it entered the next room, its head bumping against a metal step. A caption to the film claimed that the horse looked pregnant, which it did. The slaughterman followed it, sliding the door shut behind him. That would be the butchering room, and it was probably as well that the camera wasn’t able to follow.

After a few seconds, another crack could clearly be heard from behind the closed door. Cooper sat up straight. Surely the horse had been dead? It couldn’t have recovered consciousness after the butchering had begun. But the caption didn’t question that. Instead, it asked: ‘Listen carefully for a second shot. Was it directed at an unborn foal?’