This began to show a way out of the mystery; but it was by no means cleared up. Was he the man who had taken her father’s house as “Mr. Banks”? This seemed probable, and at any rate this could be easily ascertained. If so, and if “Mr. Banks” was a madman, why was he unattended by any keeper? And what, “Mr. Banks” or no “Mr. Banks,” was the meaning of these stealthy nocturnal visits? That they were so unexpected, so unwelcome, as to be inconceivable on the part of Mrs. Dale, had been abundantly proved by the fact that she had believed the visitor to be a vision of her imagination only, and not a human being. For Mabin could not doubt that the appearance which Mrs. Dale had taken for a horrible dream had been in reality the living man she had just seen. Who then could he be, and what could he want? Was the refined, sensitive face, with its sad eyes and worn mouth, the mask and not the index of the man? The more Mabin thought, the clearer it seemed to grow to her that the man was either a relation or a lover, who had gone out of his mind, and whose insanity had taken this strange form of nocturnal persecution. But then, again, if he had been insane, would not Mrs. Dale have heard of it? And was it not rather the act of a sane man than of a madman to assume a name not his own in order to hide his identity from the woman he meant to harass? Again, was the intruder the tenant of “Stone House” at all? Even of this she was not sure; and Mabin decided that this question must be answered definitely before she could think herself on the road to the discovery of the mystery. In the mean time, the door of the room through which she had passed in pursuit of the intruder being still open, she entered, and instinctively looked round, to see if he had left any trace of his presence. She drew up the blind and let the daylight stream into the corners. The room was like the rest of the house, shabby and furnished with little taste. It had perhaps been a study or a school-room, for in front of the one window there was a large leather-covered writing-table, much splashed with ink. The rest of the furniture consisted of a couple of small ottomans and half a dozen chairs, all covered with green rep, and trimmed with green worsted fringe, and of a mahogany bookcase which stood near the door. Mabin, with one glance round, had satisfied herself that nothing in the room betrayed the recent presence of an intruder, when her attention was suddenly arrested by a picture on the wall to her left. It was a portrait in oils of a man, very young, very handsome, and bearing, as she saw at once, a great resemblance to the man she had seen a quarter of an hour before escaping from the house.