When she returned, the two lovers were sitting together, Lindsay with her bruised head on Cordelia’s shoulder. She sat up to relate the events of the previous evening. Just the telling of it was enough to make her shiver with horror. And the effect on Paddy and Cordelia was no less chilling.

“You must be crazy, Lindsay,” Cordelia cried. “Going in there on your own. You could have been killed. You should have taken me with you.”

Lindsay shook her head, “No, this was one thing that had to be done solo. There’s no way Cartwright would have opened up at all if there had been two of us. He wouldn’t have fallen for the line I took. He’d simply have tried to brazen it out. So I had to trust Dart to take care of me.

“He’d fitted me out with a very good radio microphone, so that was transmitting everything said and done in the room. The cops were sitting outside in a troop of unmarked police cars with a van parked in the next-door neighbor’s drive behind the shrubbery. And for extra security, Dart’s sergeant was outside the office window with one of those limpet microphones.

“Dart was very quick at getting the operation together once I’d convinced him it was the only way to do it. He wouldn’t hear of it to begin with, but I told him if he wouldn’t help me, I’d do it on my own and the only way he could stop me was to throw me in the cells. He finally relented when I pointed out that eventually I’d be back on the streets again, and I’d go straight to Cartwright and confront him. At least when the case comes to trial I’ll have a wonderful exclusive to flog—How I Caught The Girls’ School Killer.”

“Yes. The scars will probably have healed by then,” said Cordelia drily.

“I’m sorry to be a bore,” said Paddy, “but you’ll have to bear with me. Don’t forget, I’ve not been party to all these discussions you’ve had in the course of the past week. Someone has yet to explain to me exactly what has been going on. Starting from the murder.”