“Naturally. Well, you got up here, broke in the door, and found poor Mr. Ackroyd like this. How long should you say he had been dead, doctor?”

“Half an hour at least⁠—perhaps longer,” I said.

“The door was locked on the inside, you say? What about the window?”

“I myself closed and bolted it earlier in the evening at Mr. Ackroyd’s request.”

The inspector strode across to it and threw back the curtains.

“Well, it’s open now, anyway,” he remarked.

True enough, the window was open, the lower sash being raised to its fullest extent.