Perhaps it is my training—I used to know how many million germs a fly packed about with it, and the generous benevolence with which it distributed them; I’ve forgotten—but the sight of a single fly maddens me. I said that to Mr. Patton once, and he asked what the sight of a married one would do. So I sat down by the register and waited. It was then that I made the curious discovery that the furnace belowstairs was burning, and burning hard. A fierce heat assailed me as I opened the grating. I drove the fly out of cover, but I had no time for him. The furnace going full on a warm spring day! It was strange. Perhaps I was stupid. Perhaps the whole thing should have been clear to me. But it was not. I sat there bewildered and tried to figure it out. I went over it point by point: The carpets up all over the house, lights going full all night and doors locked. The cot at the top of the stairs and Mrs. Reed staring down. The bolt outside my door to lock me in. The death of Chang. Mademoiselle locked in her room upstairs and begging for a priest. The poison on the porch roof. The head without a body on the staircase and the thing that slid over my foot. The furnace going, and the thing I recognized as I sat there beside the register—the unmistakable odor of burning cloth. Should I have known? I wonder. It looks so clear to me now. I did not investigate the staircase, for the simple reason that my skeleton key, which unfastened the lock of the door at the rear of the second-floor hall, did not open the door. I did not understand at once and stood stupidly working with the lock. The door was bolted on the other side. I wandered as aimlessly as I could down the main staircase and tried the corresponding door on the lower floor. It, too, was locked. Here was an _impasse_ for sure. As far as I could discover the only other entrance to the back staircase was through the window with the iron grating. As I turned to go back I saw my electric flash, badly broken, lying on a table in the hall. I did not claim it. The lower floor seemed entirely deserted. The drawing room and library were in their usual disorder, undusted and bare of floor. The air everywhere was close and heavy; there was not a window open. I sauntered through the various rooms, picked up a book in the library as an excuse and tried the door of the room behind. It was locked. I thought at first that something moved behind it, but if anything lived there it did not stir again. And yet I had a vivid impression that just on the other side of the door ears as keen as mine were listening. It was broad day, but I backed away from the door and out into the wide hall. My nerves were still raw, no doubt, from the night before.