"Of course, I did not think that any of Tassoc's rivals had fixed up any mechanical contrivance; but I thought it just possible that there had been some such thing for producing the whistling, made away back in the years, perhaps with the intention of giving the room a reputation that would ensure its being free of inquisitive folk. You see what I mean? Well, of course, it was just possible, if this were the case, that someone knew the secret of the machinery, and was utilizing the knowledge to play this devil of a prank on Tassoc. The microphone test of the walls would certainly have made this known to me, as I have said; but there was nothing of the sort in the castle; so that I had practically no doubt at all now, but that it was a genuine case of what is popularly termed 'haunting.' "All this time, every night, and sometimes most of each night, the hooning whistling of the Room was intolerable. It was as if an intelligence there knew that steps were being taken against it, and piped and hooned in a sort of mad, mocking contempt. I tell you, it was as extraordinary as it was horrible. Time after time, I went along--tiptoeing noiselessly on stockinged feet--to the sealed door (for I always kept the Room sealed). I went at all hours of the night, and often the whistling, inside, would seem to change to a brutally malignant note, as though the half-animate monster saw me plainly through the shut door. And all the time the shrieking, hooning whistling would fill the whole corridor, so that I used to feel a precious lonely chap, messing about there with one of Hell's mysteries. "And every morning, I would enter the room, and examine the different hairs and seals. You see, after the first week, I had stretched parallel hairs all along the walls of the room, and along the ceiling; but over the floor, which was of polished stone, I had set out little, colorless wafers, tacky-side uppermost. Each wafer was numbered, and they were arranged after a definite plan, so that I should be able to trace the exact movements of any living thing that went across the floor. "You will see that no material being or creature could possibly have entered that room, without leaving many signs to tell me about it. But nothing was ever disturbed, and I began to think that I should have to risk an attempt to stay the night in the room, in the Electric Pentacle. Yet, mind you, I knew that it would be a crazy thing to do; but I was getting stumped, and ready to do anything. "Once, about midnight, I did break the seal on the door, and have a quick look in; but, I tell you, the whole Room gave one mad yell, and seemed to come toward me in a great belly of shadows, as if the walls had bellied in toward me. Of course, that must have been fancy. Anyway, the yell was sufficient, and I slammed the door, and locked it, feeling a bit weak down my spine. You know the feeling.