Wherein lay this marked, invisible difference is impossible to say. It cannot be ascribed wholly to the imagination, because persons who had spent some time in the house, knowing nothing of the facts, had declared positively that certain rooms were so disagreeable they would rather die than enter them again, and that the atmosphere of the whole house produced in them symptoms of a genuine terror; while the series of innocent tenants who had tried to live in it and been forced to decamp at the shortest possible notice, was indeed little less than a scandal in the town. When Shorthouse arrived to pay a "week-end" visit to his Aunt Julia in her little house on the sea-front at the other end of the town, he found her charged to the brim with mystery and excitement. He had only received her telegram that morning, and he had come anticipating boredom; but the moment he touched her hand and kissed her apple-skin wrinkled cheek, he caught the first wave of her electrical condition. The impression deepened when he learned that there were to be no other visitors, and that he had been telegraphed for with a very special object. Something was in the wind, and the "something" would doubtless bear fruit; for this elderly spinster aunt, with a mania for psychical research, had brains as well as will power, and by hook or by crook she usually managed to accomplish her ends. The revelation was made soon after tea, when she sidled close up to him as they paced slowly along the sea-front in the dusk. "I've got the keys," she announced in a delighted, yet half awesome voice. "Got them till Monday!" "The keys of the bathing-machine, or--?" he asked innocently, looking from the sea to the town. Nothing brought her so quickly to the point as feigning stupidity. "Neither," she whispered. "I've got the keys of the haunted house in the square--and I'm going there to-night." Shorthouse was conscious of the slightest possible tremor down his back. He dropped his teasing tone. Something in her voice and manner thrilled him. She was in earnest. "But you can't go alone--" he began. "That's why I wired for you," she said with decision. He turned to look at her. The ugly, lined, enigmatical face was alive with excitement. There was the glow of genuine enthusiasm round it like a halo. The eyes shone. He caught another wave of her excitement, and a second tremor, more marked than the first, accompanied it. "Thanks, Aunt Julia," he said politely; "thanks awfully." "I should not dare to go quite alone," she went on, raising her voice; "but with you I should enjoy it immensely. You're afraid of nothing, I know." "Thanks _so_ much," he said again. "Er--is anything likely to happen?" "A great deal _has_ happened," she whispered, "though it's been most cleverly hushed up. Three tenants have come and gone in the last few months, and the house is said to be empty for good now." In spite of himself Shorthouse became interested. His aunt was so very much in earnest.