“It is directly over it.”
“With a window looking out over the terrace?”
“Yes.”
Again Poirot nodded. Then he said:
“Let us go to the drawing room.”
Here he wandered round the room, examined the fastenings of the windows, glanced at the scorers on the bridge table and then finally addressed Lord Mayfield.
“This affair,” he said, “is more complicated than it appears. But one thing is quite certain. The stolen plans have not left this house.”
Lord Mayfield stared at him.
“But, my dear M. Poirot, the man I saw leaving the study—”
“There was no man.”
“But I saw him—”
“With the greatest respect, Lord Mayfield, you imagined you saw him. The shadow cast by the branch of a tree deceived you. The fact that a robbery occurred naturally seemed a proof that what you had imagined was true.”
“Really, M. Poirot, the evidence of my own eyes—”
“Back my eyes against yours any day, old boy,” put in Sir George.
“You must permit me, Lord Mayfield, to be very definite on that point. No one crossed the terrace to the grass.”
Looking very pale and speaking stiffly, Mr. Carlile said:
“In that case, if M. Poirot is correct, suspicion automatically attaches itself to me. I am the only person who could possibly have committed the robbery.”
Lord Mayfield sprang up.
“Nonsense. Whatever M. Poirot thinks about it, I don’t agree with him. I am convinced of your innocence, my dear Carlile. In fact, I’m willing to guarantee it.”
Poirot murmured mildly:
“But I have not said that I suspect M. Carlile.”
Carlile answered:
“No, but you’ve made it perfectly clear that no one else had a chance to commit the robbery.”
“Du tout! Du tout!”
“But I have told you nobody passed me in the hall to get to the study door.”
“I agree. But someone might have come in through the study window.”
“But that is just what you said did not happen?”
“I said that no one from outside could have come and left without leaving marks on the grass. But it could have been managed from inside the house. Someone could have gone out from his room by one of these windows, slipped along the terrace, in at the study window, and back again in here.”
Mr. Carlile objected:
“But Lord Mayfield and Sir George Carrington were on the terrace.”