“Then, Mr. Cheyne, if all your data are right, and if the footprint was made by Miss Merrill when she was wearing these shoes, I should expect to find a mark of yellowish clay on the outside of the right shoe. Isn’t that correct?” Cheyne thought for a moment, then signified his assent. “I turn up this shoe,” French continued, suiting the action to the word, “and I find here the very mark I was expecting. See for yourself. I think we may take it then, not only that Miss Merrill made the mark on the bank, and of course made it last night, but also that she was wearing these shoes when she made it. And that would coincide with your observation.” “But,” cried Cheyne, “I don’t understand. How did the shoes get here? Miss Merrill wasn’t here since we left to go to Wembley.” “How do you know?” “Well, there’s what Dangle said. I don’t mean of course that I believe Dangle. Everything else he’s said to me has turned out to be a lie. But in this case the circumstances seem to prove this story. If he didn’t see Miss Merrill how did he know of her getting over the wall for the tracing? And if he didn’t capture her then why did she not return here? Or rather, suppose she did return, why should she go away again without leaving a note or sending me a message?” French shook his head. “I don’t know,” he answered. “I merely asked the question and your answer certainly seems sound. But now let us look about the coat.” He opened the wardrobe door. “Is the cloth coat she was wearing last night here?” A glance showed Cheyne the brown cloth, fur-trimmed coat Joan had worn on the previous evening. “And you will see further,” went on French when he had been satisfied on this point, “that there is no coat here of musquash fur. You say she had one?” “Yes. I have seen her wearing it several times.” “Then I think Mrs. Sproule saw her wearing it today. We may take it, I think, either that she returned here last night and changed her clothes, or else that someone brought in her coat and shoes, left them here and took out her others.” “The latter, I should think,” Cheyne declared. “Why?” “Because I don’t think she would come here of her own free will and leave again without sending me some message.” French did not reply. He had rather taken the view that if the girl was the prisoner of the gang the garments would not have been changed, and the more he thought over it the more probable this seemed. Rather he was inclined to believe that she had reached her rooms after the episode at Earlswood, possibly even with the tracing; that she had been followed there and by some trick induced to leave again, when in all probability she had been kidnaped and the tracing recovered by the gang. But he felt there was no use in discussing this theory with Cheyne, whose anxiety as to the girl’s welfare had rendered his critical faculty almost useless. He turned back to the young man.