Page:Christie - The Mysterious Affair at Styles.djvu/123

 at once have replaced it on her bunch; but on her bunch I found what was obviously the duplicate key, very new and bright, which led me to the hypothesis that somebody else had inserted the original key in the lock of the despatch-case."

"Yes," I said, "Alfred Inglethorp, without doubt."

Poirot looked at me curiously.

"You are very sure of his guilt?"

"Well, naturally. Every fresh circumstance seems to establish it more clearly."

"On the contrary," said Poirot quietly, "there are several points in his favour."

"Oh, come now!"

"Yes."

"I see only one."

"And that?"

"That he was not in the house last night."

" 'Bad shot!' as you English say! You have chosen the one point that to my mind tells against him."

"How is that?"

"Because if Mr. Inglethorp knew that his wife would be poisoned last night, he would certainly have arranged to be away from the house. His excuse was an obviously trumped up one.  That leaves us two possibilities: either he knew what was going to happen or he had a reason of his own for his absence."