"I don't think so, Gertrude, for in the concave of the eye I saw a piece of white metal--silver, I fancy. On that, I truly believe, the hiding-place of the diamonds is indicated."
"But if Joseph had the eye," she persisted, "although I do not see how he could have got it, he would use it to find the diamonds, and thus would not have placed it on the table."
"You forget," I said quickly, "that the hiding place of the eye is indicated in cipher, according to Mrs. Caldershaw. Joseph might have found the eye in the corner house--I don't accuse him of murder--and, being unable to read the cipher, might have placed the eye on the table to implicate you."
"Why should he, when he says that he loves me?"
"For that very reason. He is jealous of me, and knows that you will never marry him. If by implicating you he could secure your arrest, and then could save you by confessing that he found the eye and placed it on the table, he might think you would marry him out of gratitude."
"Oh, the idea is absurd," said Gertrude petulantly. "It's such a roundabout way of going to work. Let us ask Joseph?"
"No," I said cautiously; "after all what I say is merely theoretical. If Joseph did not place the eye on the table, it is no use our letting him know that it was there. It would supply him with a weapon."
"Then you don't think he----"
"I can't say what I think; as I said before," I muttered, rising to pace the room, "if I were a born detective I might unravel this mystery. As it is I can't see my way to the truth."
"If the truth is never known," remarked Gertrude, after a pause, "what does it matter?"