‘The point is, those dogs will fight and fight until they’re half-dead. You can’t take them to a vet, because – like you say – they’re illegal. And you don’t put an animal like that out of its misery by wringing its neck. You need to have somebody there with a gun, or preferably a captive bolt pistol, if you can get hold of one. They’re a lot safer than having a free bullet flying around inside a shed somewhere. Dangerous, that is.’

‘I can see that.’

‘Very dangerous,’ said Mark. ‘That way, somebody could get themselves killed.’

The Land Rover drove off again. Maybe the Ranger had just stopped to use his radio or to have a drink of tea from his flask. Maybe he was checking on the Toyota. Everybody was suspect these days. Cooper watched the vehicle’s lights heading further west, following the tight bends until they disappeared into a dark band of conifers. Out of the corner of his eye, he noticed a sudden flicker of movement, and saw a stoat run across in front of his bonnet into a clump of gorse.

‘I know this spot,’ he said. ‘It’s the place they call Suicide Corner.’

‘That’s right. It’s where all the suicides come.’ Mark pointed up the valley towards Castleton and Mam Tor. ‘Owen says the view sometimes makes them change their minds.’

The unstable slopes of Mam Tor looked like a melted chocolate cake in the darkness. Erosion of the soft shale underneath its gritstone bands meant that its sides were in continual movement, long cascades of stone sliding and slithering into the valley, where the landslips had closed the A625 many years before. Now cars struggled over Winnats Pass to where the River Eden and the River Hope sprang up on the bleak moorlands of the Dark Peak. The locals called Mam Tor the ‘Shivering Mountain’. Its vast, soft outline dominated the head of the valley. And on the very summit, the defensive ramparts of a Bronze Age hillfort could clearly be seen against the sky, even from this distance.

‘I don’t want to see Owen here,’ said Mark. ‘He might not change his mind.’

‘Mark . . .?’

‘I think Owen’s involved. He must be.’

‘But why?’

‘He’s worked in that area a long time. He must have noticed what I noticed. But he’s never said anything to me about it. He always talks about Warren Leach as if they hate each other, but I’m not sure about that.’

‘There seemed to be no love lost between them when I was there,’ said Cooper.