Poirot lifted his head suddenly.
"Shut—and now they are open. What can that mean?"
"Somebody came in that way," I suggested.
"Possibly," agreed Poirot, but he spoke absently and without conviction. After a minute or two he said:
"That is not exactly the point I had in mind, Hastings. If only one window was open it would not intrigue me so much. It is both windows being open that strikes me as curious."
He hurried into the other room.
"The sitting-room window is open, too. That also we left shut. Ah!"
He bent over the dead man, examining the corners of the mouth minutely. Then he looked up suddenly.
"He has been gagged, Hastings. Gagged and then poisoned."
"Good heavens!" I exclaimed, shocked. "I suppose we shall find out all about it from the post-mortem."