"Here we come to a dead stop," said he impatiently. "It was asserted by the police that the murder was committed with the dagger worn by your mother as part of the fancy dress."
"Yes! If you remember, it was on that evidence she was arrested."
"Well, if she wore that dagger in the sitting room, Jeringham could not have been killed with it, because the murder must have taken place while your father was trying to pacify your mother."
Claude glanced at the letter again. "My father makes no mention of the dagger in this," he said, with a puzzled look.
"No. I should like to hear what he has to say on the subject, the more so as I incline to his story rather than to your mother's."
"For what reason?"
"In her conversation with you, Mrs. Bezel—or rather your mother—said that she had threatened your father with the dagger in the sitting room of The Laurels."
"Yes. Well?"
"If you remember the evidence given by her to the police at the time of the arrest was that she had lost the dagger at the ball, and knew not into whose hands it had fallen."
Claude looked nonplussed, and knew not what answer to make. That his mother had made two different statements he was compelled to admit. He further remembered that his father had made no statement whatsoever about the dagger. Yet on the possession of that dagger turned the whole of the case. Whoever picked it up, whether at the ball or in the sitting room, must have killed Jeringham. Assuming his father's account to be true, and Claude saw no reason to doubt its accuracy, Mona could not have committed the murder, nor could Mr. or Mrs. Larcher be guilty. It therefore followed that his mother had spoken truly to the police, and for some inexplicable reason falsely to him. The dagger must have been lost at the ball, and picked up by—whom?