Straight to that familiar room at the end of the hall I went, with Strange behind me. When we had entered, he closed the door cautiously. For a moment he faced me without speaking. "You came very close to committing a murder on your way here, did you not, Dale?" I stared at him. How, in God's name, could this man read my thoughts so completely? "You would have completed the murder," he said softly, "had I wished it. I did not wish it!" I did not answer. There was no reply to such a mad declaration. As for my companion, he watched me for an instant and then laughed. He was not mad. I am doctor enough to know that. But the laugh was not long in duration. He stepped forward suddenly and took my arm in a steel grip, dragging me toward the half hidden door at the farther end of the room. "I shall not keep you long, Dale," he said harshly. "I could have killed you--could have made you kill yourself, and in fact, I intended to do so--but after all, you are merely a poor stumbling fool who has meddled in things too deep for you." * * * * * He pulled open the door and pushed me forward. The room was dark, and not until he had closed the door again and switched on a dim light, could I see its contents. Even then I saw nothing. At least, nothing of importance to an unscientific mind. There was a low table against the wall, with a profusion of tiny wires emanating from it. I was aware that a cup shaped microphone--or something very similar--hung over the table, about on a level with my eyes, had I been sitting in the chair. Beyond that I saw nothing, until Strange had moved forward and drawn aside a curtain that hung beside the table. "I made you come here to-night, Dale," he murmured, "because I was a bit afraid of you. Your comrade, Hartnett, was an ignorant police officer. He has not the intellect to connect the series of events of the past day or two, and so I did not trouble myself with him. But you are an educated man. You have made no demonstrations of your ability in the field of science, but--" He stopped speaking abruptly. From the room behind us came the sound of a warning bell. Strange turned quickly and went to the door. "You will wait here, Doctor," he said. "I have another caller to-night. Another one who came the same way as you!" He vanished. For a short interlude I was alone, with that peculiar radio-like apparatus before me. It was, for all the world, like a miniature control room in some small broadcasting station. Except for the odd shape of the microphone, if it was such I could detect no radical difference in equipment. * * * * * However, I had little time for conjecture. A patter of footsteps interrupted me from the next room, and a frightened, feminine voice broke the stillness of the outer study. Even before the owner of that voice stepped in to my presence, I knew her.