The conversation with Juliet convinced Jennings that she knew of something connected with the matter, but was determined to hold her tongue. The fact that this knife was in her possession showed that she was aware of some fact likely to lead to the detection of the assassin. She might have found it when she came after the death to Rose Cottage, but in that case, had she nothing to conceal, she would have shown it to the police. Instead of this, she hid it in the attic. Jennings congratulated himself on his dexterity in securing this piece of evidence. There was no doubt in his mind that this was the very knife with which Miss Loach had been stabbed. "And by a man," thought Jennings. "No woman would have such a weapon in her possession; and if she bought one to accomplish a crime, she would purchase a stiletto or a pistol. It would take a considerable exercise of muscle to drive this heavy knife home." Jennings considered that the only person who could make Juliet speak was Cuthbert. It was true that she already had declined to make a confidant of him, but now, when there was a chance of his being arrested--as Jennings had hinted--she might be inclined to confess all, especially if it was Cuthbert she was shielding. But the detective fancied her brother might be the culprit. On the night of the murder, both had left the Marlow Theatre, which was near Rexton, and Juliet declined to say where they went. It might be that both had been on the spot about the time of the commission of the crime. Again, unless Miss Loach had admitted her assailant, he must have had a latch-key to let himself in. From the fact that the poor woman had been found with the cards on her lap in the same position in which Susan had left her, Jennings was inclined to think that the assassin had struck the blow at once, and then had left the house at the half hour. But how had he entered? There did not appear to be any secret entrance, and no one could enter by the windows; nor by the door either without a latch-key. The further Jennings examined into the matter, the more he was puzzled. Never had he undertaken so difficult a case. But the very difficulty made him the more resolute to unravel the mystery.