Jessica shook her head. “There were quite a few people milling around outside the hall, but they all looked as if they were going to the concert. I recognized one or two of them because I’ve seen them in the town, and some of them because they’re parents. I saw Caroline’s father getting out of his car when I came across, but I don’t think he can have stayed for the concert because his car had gone when I came back with Miss Callaghan. But you’d better ask Caroline about that.”

Lindsay and Cordelia exchanged a look. Yet another complication had emerged. “What happened when you got to the hall?” Cordelia asked.

“I asked Caroline if she’d seen Miss Callaghan and she said she thought she was still backstage. I went through and asked one or two people if they’d seen her, but everyone was too busy to have noticed. I went down the side passage as far as the storeroom to see if she was there, but there was no sign of her. Then I went back to the main corridor and looked into the rest of the music rooms. I finally found her just outside Miss Macdonald’s room, round the corner. I told her what had happened and she said I’d done the right thing and came straight back with me. She stayed in Longnor then for about half an hour.” She ground to a halt.

“Did it seem to you as if Miss Callaghan had just come out of Miss Macdonald’s room?” asked Lindsay cautiously.

“I don’t think so. There are a few steps that lead down to the room. She was about halfway down them, looking out of the window down the front drive.” She hesitated, then said in a rush, “She seemed to be miles away. I had to speak to her twice before she heard me.”

Lindsay and Cordelia looked at each other, both filled with dread at the thought of how this new evidence could be made to sound by a good prosecuting counsel. Then Cordelia roused herself and said, “Did she seem upset or agitated at all, Jessica?”

“No, she just seemed to be very thoughtful. Preoccupied. Usually she’s very lively and chatty. It was as if she had something on her mind. Not as if she’d just killed someone, if that’s what you mean—not like that at all. She couldn’t have done that, could she? Not someone like Miss Callaghan?”

“We don’t believe so, no,” said Lindsay. “Are you sure you didn’t go any further down the side passage than the storeroom? You said you checked all the other music rooms on the main corridor. Didn’t you check Music 2?”

“No, I definitely didn’t go all the way down the corridor.”

“Why not?”