“You’ve asked everybody in the area to report break-ins or stolen food immediately, have you?” I said. “They have to eat and shelter somewhere.”

“Exactly. With the kind of weather we’ve just had, someone must be hiding them, but we’ve pretty much searched door to door. Most of the local people have lived here all their lives. They’re not the kind of people to be harboring criminals.”

“I’m not sure it is your convicts we’re looking at,” Granddad said slowly. “In my time on the force I came up against a lot of criminals. Most of them were not too bright and if they were going to kill someone they did it with the first thing that came to hand—coshing someone over the head with a brick, stabbing them, or shooting, if they had a gun. And they usually chose the same way too. They’d leave behind a blueprint we could identify. If these are murders, they are clever methods of killing—someone with a good brain is killing in very different ways—heaven knows for what reason. Either that or more than one person is involved. So we have to ask ourselves why. Why would a man bother to electrocute someone at a switchboard when he could presumably follow her home in the dark and cosh or stab her? Until we can get inside his head, we’re not going to be able to stop him.”

“I suppose you’re right,” the inspector said. “But as it happens these convicts were not your usual thugs. One was a bank teller, reckoned to be the brains behind a big train robbery. Another was an escape artist in the theater. You know, Britain’s answer to Houdini. We reckon he was the one who got them out of their shackles. He went bad and turned to safecracking. And the third used to do a comic music-hall act with his wife. The old colonel and the innocent young girl.”

“Sounds harmless enough,” Granddad said.

“I don’t know about that,” the inspector said. “When there was no more money to be made from music halls they started robbing their landladies, or conning them out of their life savings. Some of the old biddies met an untimely end, but we could never prove that this bloke was actually guilty of murder.”

“What happened to the wife? Did she go to jail too?” Granddad asked.

“She committed suicide. Drowned herself off Beachy Head in Sussex.”

“So not from around here, then?”

“None of them were. Driving me mad, that’s what it’s doing.”

He took a long swig of tea, then set down the teacup.