"No. I suppose not. And yet, it is simple enough. That half-smoked cigarette and nothing else is the basic reason for the arrest of the three men now in your hands."
Monsieur Lefevre smiled. "Be good enough," he said, "to explain."
"Very well, I will. But first, let me indicate to you my course of reasoning. When I originally found the cigarette, I regarded it as of very small value, from the standpoint of evidence. It happened to be lying in the grass at the point where the crime occurred; but during the week or more which had elapsed between the stealing of the boy and my examination of the ground, a hundred people might have walked over the spot. I took it, because I realized that it might have a bearing on the case, and I have learned to discard no clue, however trifling it may appear, until it has been proven valueless.
"Now to go back to the cigarette, I observed at once that it was of American make, yet of such small size as to have been either used by a woman, or by a man of rather effeminate taste.
"Now if the cigarette had been used by a woman, it meant one of two things. Either it was used by Mary Lanahan herself, in which case it apparently proved nothing, or by some other woman who was there with her, and who might have had a hand in the kidnapping.
"On the other hand, if used by a man, it pointed clearly to the chauffeur, Valentin, for several reasons. He was a friend, a former lover, of the nurse. He had been discharged by Mr. Stapleton for dishonesty. He was, I had reason to know, of rather a weak and effeminate type. The cigarette was of American make, and he had but recently come from America. These things pointed to Valentin. The fact that the nurse was in love with him would cause her to shield him. I determined to try the matter out at once.
"As soon as I returned to the house, therefore, I confronted her, and asked her if Valentin smoked gold-tipped cigarettes. I did this, not because I expected to get any reply of value, but because I wished to observe her manner, her face, when I flung the question at her.
"She was greatly startled. She denied that Valentin smoked. Fifteen minutes later, she sent him a message to destroy the cigarettes.
"I at once concluded that they were working together, and were both guilty, a conclusion in which, however much I was justified by the evidence, I was quite wrong.
"Then came the attempt on the part of someone—the man with the black beard, I am told—to steal the cigarettes from Valentin. I learned that the man was followed to Mr. Stapleton's house.