Lindsay took a deep breath and began. “I now know how precarious James Cartwright’s financial position was. He admitted last night he didn’t have a brass farthing. Inspector Dart told me he’d made some bad property deals lately. He had already raised a lot of capital on the strength of his time-share scheme and it was absolutely crucial that the playing fields deal succeeded. Had he not pulled it off, he would have been forced into liquidation and bankruptcy. He couldn’t face that prospect; he enjoyed his lifestyle too much. And he was worried about losing Sarah’s affection and respect if he couldn’t give her the life she was used to.

“He tried to bribe Lorna not to play that night. Even though the tickets had already been sold, if Lorna had pulled out, a lot of people would have been looking for their money back. And it would have completely discredited any further attempt to raise the money. But Lorna wouldn’t hear of it. She was enjoying herself far too much watching people being upset by her presence. Also, in spite of herself, I think she did care about the school. And she had sufficient integrity as an artist not to let her public down. So she refused, and in deeply insulting terms. He was thwarted and also very angry. That’s when he thought of trying to murder her. He had reached the end of his tether, something Lorna couldn’t have known. He was desperate enough to be dangerous.

“He knew the school layout very well. So, when everyone was at dinner, he went to the music room and helped himself to a cello string. He was probably wearing his driving gloves, because the police haven’t found any prints. He probably also checked that the window catches were still easy to manipulate. Then he fetched the scaffolding and set it up.

“He dashed back to the Woolpack and bought a pint. He must have downed it in a oner, because by about twelve minutes past seven he was back at the school. He went to Longnor—I guess because he knew the cloakroom was near the door and it would be quieter than the main building—and helped himself to a toggle, presumably having realized by then that the string was sharp enough to cause bad cuts even through gloves if he used it on its own. That’s almost certainly when Sarah saw him. I think she was probably coming downstairs to go for a walk at the time, or to go down to the gym to do some exercises, perhaps.

“I’m guessing a bit now. But I think she followed him, catching up with him as he was preparing the garrote or climbing up the fire escape to the scaffolding. He sent her back, telling her to forget she’d seen him.