Liz walked over to the window and looked out on to a small back garden. There was a gate in the rear fence leading to a lane. Easy to get in and out without being spotted. The window had been crudely levered open, exactly the same as the other three stabbings. "Do you know if she's noticed anyone watching the house, or following her?"

"We're not on speaking terms," said Armitage. "We wouldn't be in here tonight if it wasn't an emergency. I was one of the people her old man nicked a car radio from, so we're not coming in for tea and biscuits and a chat, are we?"

Liz snapped her notebook shut. She would have to come back again tomorrow when the mother had calmed down. "Well, thank you very much. Try not to touch anything. There'll be a fingerprint man here in the morning."

Mrs. Armitage walked with her to the front door. "Do you think you'll catch him?"

"We'll get him," said Liz. She wished she shared her spoken optimism. A maniac who had a thing about seeing blood on children. They had no description, no fingerprints they didn't even know if it was a man or a woman, and all of the known sex offenders she had painstakingly questioned had cast-iron alibis. "We'll get him all right." The front door slammed shut behind her, but she could still hear the mother wailing.

In the car she switched her radio back on and they told her about the dead boy. She fished out the map and tried to find how to get to Patriot Street.

"She had her damn radio off!" said Wells incredulously. "What does the silly cow think we give her a radio for -just to keep in her bloody handbag?" The phone rang. "Yes?" he snapped.

It was Mullett and he sounded just the tiniest bit drunk. "My wife tells me you've been trying to reach me, sergeant."

Wells clapped his hand over the mouthpiece and yelled for Lambert to call back the area car. Then he told Mullett about the murdered boy.