"Eight feet up," he said, "and there's an unmarked flower-bed underneath. Nobody even climbed up here, much less disturbed those curtains, climbed in, and got twelve or fifteen feet across hell's own squeaky floor to the table — all without being seen or heard. It's just impossible. Come and look for yourselves."

He switched off the torch. He turned round from the window and ran a hand through his hair. The tall black-and-scarlet devil seemed to have become a much bewildered and harassed young man.

"But we didn't do it," he protested.

"No." Rich's voice was sharp. "We can be certain we didn't do it. Any of us. We can — what's the word? — give each other an alibi."

"But somebody changed the daggers!"

"How?" asked Ann.

"You don't suppose—" Sharpless hesitated—"you don't suppose Fane did it himself?"

"When," inquired Rich, "he knew he was going to he stabbed with it? And, in fact, insisted on this when I wanted to stop the experiment?"

They looked at each other.

Rich fastened the button of his shabby dinner jacket, and squared his shoulders. Though he seemed the most disquieted person there, you would also have said that he was the most resolute.