Anthony came and looked. “Pity! Still—it’s my own fault—I ought to have anticipated this. Delays are dangerous.”

He crossed to the window, and looked out, leaving the bathroom door open behind him.

“Precious little chance of any exit or entrance this way,” he said. “A cat would find a foothold difficult.”

“Why?” I asked. “You didn’t really consider that as a possibility, did you?”

“I consider everything as a possibility, Bill—till I know it’s not. Hallo—that’s rather interesting.” He pointed to the wash-hand basin.

“What is it?” I said.

“The stub of a cigar! Not finished either. Funny place for a cigar.”

“Not altogether,” I ventured. “Suppose Prescott was smoking a cigar when he came to bed that night and came in here to wash his hands. It would be a very natural thing for him to put it there while he washed them.”

Anthony nodded approvingly. “Yes! And when he’d finished washing them?”

“Well?”