He trod through the silent house, going into the kitchen first, thinking about how the media were going to go crazy when they heard about this one, about the panic that would ensue. And the pressure on his team, which was intense already – it didn’t seem possible that it could get worse, but he knew it was about to. It was like going from 2-0 to 3-0 down in the first half of a match you couldn’t afford to lose.

Three children in one small area of London within a week. A living room, a car and now a bedroom. The person the press were calling the Child Catcher was getting braver, daring to go upstairs now, like the urban fox that had caused almost as much hysteria when it crept into someone’s house and tried to drag their baby out. Of course, he shouldn’t assume that it was the same person in all three cases. But unless it was a copycat – and Patrick had never actually come across a copycat criminal in over a decade of police work – or some kind of insane social phenomenon, this had to be the work of the same person. A person whose need to commit these crimes was escalating rapidly.

He slipped on a pair of disposable gloves and examined the back door, peering through into the darkness of the garden.

Something thumped against the glass and he jumped. It was a cat, a ginger specimen, jumping up at the door, trying to get in.

‘Better catch yourself a mouse tonight, mate,’ he said.

The keys were in the lock. He made a note in his pad and looked around the kitchen. A lone wine glass stood on the draining board. A takeaway pizza box poked out of the bin. There was a very faint smell of cigarette smoke. Was that what had happened? Alice had opened the back door to have a crafty fag while her parents were out? And she was too frightened to admit it? Patrick could understand that if it was the case. He still didn’t smoke in front of his parents – not even his fake fag.