He looked suspiciously at her. The blurred look left his features as comprehension drove the effect of the drink away. “I don’t know what you mean,” he replied belligerently. Lindsay said nothing. “Oh, for Christ’s sake, you’d better come in. I don’t want a scene on the doorstep,” he sighed.

“You’ve got a bloody cheek,” he complained bitterly as he led her down the hall to the office. Once there, he rounded on her. “Sit down. Now what’s all this crap about the police?”

“I thought I’d like to put a proposition to you,” said Lindsay. “Forget about blaming me for Sarah’s death. It’ll go down fine with anybody else, but it won’t wash with me.”

His expression was calculating. “And what’s that supposed to mean?”

Lindsay managed to maintain the tough façade she had adopted, though inwardly she was quaking with fear. “Last Saturday night. Saturday’s not been a lucky day for you lately, has it? First Lorna, then Sarah.”

A flash of genuine pain crossed his face. “You’re not fit to speak her name,” he spat.

“Leave it out, Cartwright,” Lindsay replied. “I know how Lorna was murdered, which, thanks to the conversation I had yesterday with Inspector Dart, is getting to be common knowledge. But only you and I know who murdered her.”

A new wariness appeared in Cartwright’s face. “Sarah confessed, you know. Not easy for me to believe, but my daughter did that to try to save my business.”

“Save it for the funeral oration, Cartwright. Though, funnily enough, those are the first true words you’ve spoken in this whole sorry business. Sarah did just that. She confessed to save both your business and your neck. She was bright enough to know that alive her ‘confession’ wouldn’t stand up to a five-minute police interview. There were too many details of the killing she simply didn’t know. And the reason for that is that it wasn’t Sarah who killed Lorna. It was you.”

He sat and stared at her, his hands balling into fists on the desktop. “You must be mad. I’ve got an alibi. The police have checked. It was Sarah, God damn it, it was Sarah!”

“I’ve checked it out too. And it’s not tight enough. Lorna was killed between half-past seven and twenty to eight. You could just have done it on the basis of the times you were actually seen in the two pubs. Sarah couldn’t have done it, though. By twenty-five to eight she was in Longnor. That only leaves you with the necessary knowledge and skill to assemble that scaffolding and kill Lorna.”

“You can’t prove that. If you could, or thought you could, you’d be telling the cops, not me.” He got to his feet and started pacing about the office restlessly.