Owen Fox’s house was cluttered and warm. There was a stunning view out of the back window, casting light into the back rooms. But the rooms at the front of the house, below street-level, must have been permanently dark.

There were a couple of cats somewhere – black, elusive shapes that slunk out of the way when the police appeared. They darted in and out of a cat flap on the back door and peered malevolently through the windows from outside. Maybe they just wanted feeding, but it was a job they would have to delegate to the neighbours.

Between thick walls, the rooms were crammed with old furniture. A lot of the pieces might have been items Owen had inherited from his parents, or even his grandparents. They looked to be full of history, an integral part of their surroundings. A solid-fuel Raeburn stove stood in the kitchen, the plaster above it covered in a layer of red dust.

‘It’s weird,’ said Hitchens. ‘The computer looks really out of place.’

‘Computer?’

‘In there.’

The computer stood among heaps of books, with a used coffee mug on the mouse mat and Friday’s Buxton Advertiser draped over the printer. One of the detectives working with DI Armstrong’s team had arrived and booted it up. He already had a Microsoft Windows image on screen.

On a small shelf behind the desk there was a framed photograph of Owen. He was standing against the side of a Land Rover in his Ranger uniform. The photo was a few years old, but Owen’s hair and beard were already grey.

‘Apparently the kids call him Father Christmas,’ said the detective cheerfully.

‘So I’m told.’

‘Plug the printer in for me, mate. I’m going to print some log files out.’

Cooper looked for the leads, found a whole tangle of them at the back of the table, and tried to trace the power and data leads for the printer.

‘What’s this one?’

‘That’s the phone connection.’

‘I can’t see a modem here.’

‘It’s an internal.’

‘He’s got access to the Internet?’

‘Oh, yes,’ said the detective. ‘I can’t wait to see what Santa’s got on his hard drive.’