Cal and Stride sat without speaking, smoking their cigarettes, staring into space, apparently at peace with the world. Cooper recalled that there had been cigarette ends in the inventory of items recovered by the scenes of crime team near Jenny Weston’s body. But they had been Marlboro, not handmade roll-ups.

Above the VW van, a birch had rooted itself on a precarious ledge in the quarry side. Its lower branches were hung with small metal objects, bits of tinfoil and sections of baked bean cans tinkling and clanging in the wind.

‘And what’s all that lot supposed to be?’ asked Tailby. ‘Some new way of doing the washing-up?’

‘Tree art,’ said Hitchens. ‘Bevington has written some poems that are stuck to the chimes. They’re meant to create an atmosphere of peace and harmony, he says. Do you want to go and have a closer look?’

‘No, thanks. Too much harmony is bad for me.’

Tailby glared down at the van. To Cooper, it seemed that it was taking a great effort for Cal not to look up and stare back.

‘Can we positively eliminate them as suspects?’ asked Tailby.

‘They have no apparent connection with the victim, and there’s no motive that we know of. There is no witness evidence to tie them in any closer to the scene than this.’

‘What about their shoes?’

‘I got a quick look,’ said Cooper. ‘Calvin Lawrence is wearing trainers, and Bevington has a pair of Doc Martens. Neither would match the partial print we found.’

‘They may have a pair of boots in the van. I know they don’t look as though they have much, but even these two could own more than one pair of shoes.’

‘We’d need a search warrant to look in the van. We don’t have reasonable suspicion.’

Stride lay back on the rock, letting his coat fall open, resting his head back so that he was gazing at the sky. His hands were resting on his face near his eyes, but the fingers were still. The smoke from his roll-up drifted straight up for a few feet, then was caught in the wind and dispersed. Whatever he could see up there in the sky caused him to smile with some deep, inner pleasure. The smile was so sudden that it made the detectives look up as well. But there was nothing to be seen except clouds scudding high across the moor. The clouds were growing darker. There could be rain soon.

‘If you think those wind chimes are strange, Cooper has something else to show us,’ said Hitchens.