So we left him, and Moore said, as he bowed us out, that we would take a look round Mr. Tracy’s apartments upstairs.

“Not just now,” Ames said. “They are about to take the body away.”

“That won’t matter. We won’t incommode them,” and grasping my arm, Moore fairly hustled me along with him toward the staircase.

We went up to the wing containing the luxurious suite of the dead man.

Looking at it more critically than before, I was delighted with its beautiful furnishings and appointments. We paused in the sitting room, for the undertaker’s men were in the bedroom.

Moore began to scrutinize the room. He did not get down on his hands and knees, and show the accepted detective demeanour of “a hound on the scent.” But he went about the room with his quick eyes darting here and there for possible indication of an intruder.

The usual appurtenances of the master’s occupancy he left apparently unnoticed, but he examined the door sill and the window sills.

The windows, there were two large ones, gave on the lake, or rather, on that dark pool-like stretch of water called the Sunless Sea.

“Come and look out here, Norris,” he said. “Can you imagine any one jumping or diving into that bottomless pit?”

“Yes,” I returned, “I can easily imagine it. But he would have to be a master diver and a master swimmer. Also, a fearless man and a desperate one.”