whole theory. You'll have to confess yourself a fool to Roger Odell." As I blundered at the lock in haste and fear that someone might pass, or that this might be one of T. Paulling's rare days at the flat, I was aghast at my late self-confidence. Face to face with the test, it seemed impossible that my-boast to Odell and Carr could succeed. I felt callow and stupid, altogether incompetent. The key seemed too large and the wrong shape, which meant that the mystery of the brothers' death was closed to me, like the door. A voice not far off made my nerves jump, and—the key slipped into the lock! From somewhere above or below came the sound of voices, but I could not be seen from the lift. Almost before I knew what I was doing or what had happened, I was on the other side of the door, in a dark and stuffy vestibule. The sound of voices was suddenly stilled. It was as if with a single step I had won my way into another world. I drew a long breath of relief after the strain, for the silence and darkness said that the tenant was not at home, and I might hope to have the flat to myself. I groped for an electric switch, touched it, and flooded the vestibule with light. It was small, with nothing to distinguish it from any other vestibule of any other well-furnished flat. Beyond led a narrow corridor which, when lit, showed me several doors. I opened the nearest, switched on another light, and found myself on the threshold of a moderate-sized sitting-room or study, with bookshelves ranged along one of the walls. The window was so heavily curtained that I had no fear of the sudden illumination being noticed from the street. The air was heavy and smelled of moth powder. The mahogany table in the centre of the room and the desk under the window were coated with thin films of dust, but everything was stiffly in order: no books lying about, no woman's work, no trace of cigarette ash, dropped glove, nor pile of newspapers with a tell-tale date. I walked over to the desk and, pulling out the swivel chair, sat down. In the silver inkstand the ink had dried. In a pen-rack were two pens, one stub, the other an old-fashioned quill, both almost new, but faintly stained with ink. Neither, it struck me, could have been used more than once or twice. There were several small drawers; all were empty. No paper nor envelopes, no sealing-wax nor seal, not so much as an end of twine. But the blotting-pad—the only movable thing on the desk beside the inkstand and pen-rack—was more repaying. It also appeared to be nearly new. Just inside the soft green leather