‘You can bet he wasn’t really awake until five thirty,’ O’Malley said to Lightman in a low voice, as they left. ‘His window’s at the front. Surely, if he’d been awake, he’d have heard someone being murdered in the next-door garden.’

‘Unless they did it awfully quietly,’ Lightman replied with a trace of a smile, ‘out of consideration for the neighbours.’

‘It’s been wiped,’ McCullough said, her gloved finger hovering over the handle of the knife to show him the lack of blood over the patterned grip. It would have been a beautiful object without the brownish crust over the blade. A black grip patterned with elaborate silver detailing. A long, tapered blade curved to a hunting point.

There were three of them hunkered over the body of the young man. The pathologist had arrived, and Jonah had been satisfied to note that it was Dr Peter Shaw attending. Jonah had worked with him only once before, but his calm, measured approach had been a key part of achieving a murder conviction. He had turned out to be good on the witness stand, too. Less flappable than Jonah had expected of a fairly young man.

‘No prints, then,’ Jonah said, looking away from the perfectly crafted weapon. ‘But it’s pretty distinctive, isn’t it?’

‘It is. There’s a chance you could track down its owner,’ McCullough said, and then, to Shaw, ‘I’m interested in the smears. It looks like someone wiped the handle clean of prints and deposited it here.’

‘He wasn’t stabbed here,’ Jonah said.

It wasn’t a question. It had been clear to him from the lack of pooled blood below the body. He’d seen victims of knife crime before. The extraordinary spread of blood. The way it saturated everything. This looked to him like the end of a journey, one that must have involved a great deal of blood loss along the way.

‘No, he wasn’t.’ It was the pathologist who answered this time. He glanced towards the gate. ‘Has your team marked up the footprints yet?’

‘Yes, done,’ McCullough said, and they made their way carefully out onto the road.

The team had now put a cordon up round the pavement and verge, and McCullough led the two of them to the edge of the road.

‘Here,’ she said, gesturing to several pieces of plastic that had been skewered into the snowy grass. Alongside each, there was a depression in the snow, and in some places the snow was stained with what seemed to be blood. ‘They start at the kerb.’

Jonah turned to look at the road. ‘Are they definitely his?’

‘They seem to match his shoes,’ McCullough replied, ‘and I think it would be difficult for someone to carry him.’