But he had too much natural chivalry for this. His feelings as a man got in the way of his instinct as a detective. Nevertheless, he felt positive that his suspicions in regard to this nephew of Mrs. Clemmens were correct, and set about the task of fitting facts to his theory, with all that settled and dogged determination which follows the pursuit of a stern duty unwillingly embraced. Two points required instant settling. First, the truth or falsehood of his supposition as to the identification of the person confronted by Miss Dare in the Syracuse depot with the young man described by Miss Firman as the nephew of Widow Clemmens. Secondly, the existence or non-existence of proof going to show the presence of this person at or near the house of Mrs. Clemmens, during the time of the assault. But before proceeding to satisfy himself in regard to these essentials, he went again to the widow's house and there spent an hour in a careful study of its inner and outer arrangements, with a view to the formation of a complete theory as to the manner and method of the murder. He found that in default of believing Mr. Hildreth the assailant, one supposition was positively necessary, and this was that the murderer was in the house when this gentleman came to it. A glance at the diagram on next page will explain why. The house, as you will see, has but three entrances: the front door, at which Mr. Hildreth unconsciously stood guard; the kitchen door, also unconsciously guarded during the critical moment by the coming and going of the tramp through the yard; and the dining-room door, which, though to all appearance free from the surveillance of any eye, was so situated in reference to the clock at which the widow stood when attacked, that it was manifestly impossible for any one to enter it and cross the room to the hearth without attracting the attention of her eye if not of her ear. [Illustration: Diagram] To be sure, there was the bare possibility of his having come in by the kitchen-door, after the departure of the tramp, but such a contingency was scarcely worth considering. The almost certain conclusion was that he had been in the house for some time, and was either in the dining-room when Mrs. Clemmens returned to it from her interview with Mr. Hildreth, or else came down to it from the floor above by means of the staircase that so strangely descended into that very room.