“I tell you I didn’t telephone you,” Mrs. Gentrie said indignantly. “If you say that I did, you’re saying something that’s not so.”
“Of course,” Mason went on, “your voice sounded somewhat strained, which was only natural in view of the fact that you were hysterical, but there were certain little mannerisms of expression which were undoubtedly yours.”
“You’re crazy,” Mrs. Gentrie announced flatly.
“You also told me,” Mason said, “something which came as a very valuable piece of information — that Lieutenant Tragg had found the can I had planted on the shelf, and removed the top, that he had then placed another decoy can there. That explained a feature of the case which had hitherto puzzled me.”
Mrs. Gentrie said, “That’s true about lieutenant Tragg. He told me not to say anything about the tin; so I didn’t. I didn’t have any idea you’d put the tin there.”
Tragg turned to Mason. “You planted that?” he asked.
Mason nodded. “To help clear up the case. I could have had it solved earlier if it hadn’t been for your interference there.”
“But I put a tin back to take its place,” Tragg said, “and had the same code message copied and placed in the lid.”
Mason smiled. “But don’t you see that the person for whom the message was intended was present when you opened the tin, and so actually got the message without the necessity of having the can removed from the shelf. You crossed me up there, Lieutenant.”
Tragg frowned, looked at Mrs. Gentrie, and said, “Mrs. Gentrie, I’m going to ask you...”