"And now for the little exhibition of which I spoke, Dale," he murmured. "Your detective friend, Hartnett, has been under my power for the past three hours. You see, it was safer to control his movements, and be sure of him. And now, to be doubly sure of him, perhaps you would like to see him kill himself!" I stepped forward with a sudden cry. Strange said nothing: his eyes merely burned into mine. Once again I felt that strange, all-powerful control forcing me back. I retreated, step by step, until the wall stopped me. Yet even as I retreated, a childish hope filled me. How could Strange, working his terrible murder machine, concentrate his power on any individual, when the whole of London lay before him? * * * * * He answered my question. He must have read it as it came over me. "Have you ever been in a crowd, Dale, and watched a certain individual intently, until that particular individual turned to look at you? The rest of the crowd pays no attention, of course, but that one man. And now we shall make that one man murder himself!" Strange turned slowly. I saw his fingers creep along the rim of the table, touching certain wires that came together there. I heard a dull, droning hum fill the room, and, over it, Strange's penetrating voice. "When I am finished, Dale, I shall probably kill you. I brought you here merely to frighten you, but I believe I have told you too much." With that new horror upon me, I saw my captor's lips move slowly.... And then, from the shadows at the other end of the small room, came a low, unemotional voice. "Before you begin, Strange--" Michael Strange whipped about in his chair like a tiger. His hand dropped to his pocket, so swiftly that my eyes did not follow it. And as it dropped, a single staccato shot split the darkness of the room. The scientist slumped forward in his chair. The dull, whirring sound of that hellish machine had stopped abruptly, cut short by the sudden weight of Strange's lunging body as he fell upon it. I saw the livid, fiery snake of white light twist suddenly upward through that coil of wires: and in another moment the entire apparatus shattered by a blinding crash of flame. * * * * * After that I turned away. Whether the bullet killed Strange or not, I do not know: but the sight of his charred face, hanging over that table of destruction, told its own story. It was Inspector Drake who came across the room toward me, and took my arm. The smoking revolver still lay in his hand, and as he led me into the adjoining room, I saw that Margot had already found refuge there. "You see now, Dale," Drake said quietly, "why I let Hartnett go with you before? If Strange had suspected me, I should have been merely another victim. As for Hartnett, he has been under constant guard down at headquarters. He's safe. They've kept him there, at my instructions, in spite of all his terrific efforts to leave them."