He stood beside me in silence, his candle in his hand. Then the tall, lean figure inclined towards me. “I say, Watson,” he whispered, “would you be afraid to sleep in the same room with a lunatic, a man with softening of the brain, an idiot whose mind has lost its grip?”

“Not in the least,” I answered in astonishment.

“Ah, that’s lucky,” he said, and not another word would he utter that night.