She waved her notes at Lindsay. “Look. I’ve worked it out. Six o’clock he comes back to the school. He collects the scaffolding—don’t forget, he was bound to know it was there, which Barrington may not have done. Then it’s up the fire escape to the kitchen roof, where he assembles the frame. He would also know what he was doing, he’s been a builder for years. If anyone knew how to erect that frame, it was him. He’s still a strong-looking bloke. And he installed those windows. He’d know exactly what he was about, breaking in through them without making a noise.

“So he bolts the scaffolding to the railings. Then he nips into the music department and makes his preparations. I’m not sure why he took the toggle from Longnor—maybe he’d parked his car near there and it was only on his way back that he realized he’d need something to protect his hands. Anyway, he drives to the Woolpack, has a very quick pint, and shoots back here. Along the scaffolding he goes, flicks open the window catch, pulls himself over the sill, and bingo! Even if Lorna had heard him and there had been a struggle, he’s strong enough to have overpowered her easily. Then it’s off into the night, pausing only to dismantle the scaffolding. He could have come back and taken it away at any time. What do you think?”

Lindsay grimaced wryly at Cordelia and lit a cigarette. “Listen, sunshine,” she said, trying but failing to keep her voice light and jokey, “I’m supposed to be the Sherlock Holmes around here. You’re supposed to be the dumb Dr. Watson who stands back in amazement when the great investigator propounds her extravagant but impeccable theories. Your role is to provide an appreciative audience for my little gray cells, not to steal my thunder. Nevertheless . . . you’re absolutely right. I was too hasty in ruling him out. It’s just as well one of us is cautious.”

Cordelia made a mocking bow at Lindsay. “Your humble servant acknowledges her menial role. But I must be allowed at least one good idea per case. Is that what I’m supposed to say?” She looked hard at Lindsay. “I don’t care what you think you’ve got to prove, Lindsay. Don’t try to do your proving on me. It’s not necessary.”

Lindsay flushed. “I was only joking,” she muttered defensively.

Cordelia winked broadly at her. “Better luck next time,” she said, gently.

Together they walked across to breakfast and were lucky enough to find Chris Jackson sitting alone at a table plowing her way through a mound of toast and bacon. They sat down beside her after collecting boiled eggs and rolls.