"The sensations which I was undergoing became unendurable," went on Lambert, in a low, hoarse voice. "I was forced to cry out in pain and confusion. "Miss Crawford evidently heard my call, for a few moments later, just as the terrific unknown force reached its apex, she dashed into the laboratory, and stepped across the plate you see there. "I was powerless. Though I shut off the current by a superhuman effort, she--she was gone!" Lambert put his face in his hands, a sob shook his broad shoulders. "Gone?" repeated Phillips. "What do you mean, gone?" "She disappeared, before my very eyes," said the professor shakily. "Torn into nothingness by the fierce force of the current or sound. Since then, I have been trying to reproduce the conditions of the experiment, for I wish to bring her back. If I cannot do so, then I want to join her, wherever she has gone. I love her, I know now that I cannot possibly live without her. Will you please leave me alone, now, so that I can continue?" Doherty laughed derisively. "What a story," he jeered. "Keep quiet, Doherty," ordered Phillips. "Now, Professor Lambert, your explanation of Miss Crawford's disappearance does not sound logical to us, but still we are willing to give you every chance to bring her back, if what you say is true. We cannot leave you entirely alone, because you might try to escape or you might carry out your threat of suicide. Therefore, I am going to sit over there in the corner, quietly, where I can watch you but will not interfere with your work. We will give you until midnight to prove your story. Then you must go with us to the district attorney. Do you agree to that?" * * * * * Lambert nodded, eagerly. "I agree. Let me work in peace, and if I do not succeed then you may take me anywhere you wish. If you can," he added, in an undertone. Doherty and the others, at Phillips' orders, filed from the laboratory. "One thing more, professor," said Phillips, when they were alone and the professor was preparing to work. "How do you explain the fact, if your story is true, that Miss Crawford was killed and made to disappear, while you yourself, close by, were uninjured?" "Do you see these garments?" asked Lambert, indicating some black clothes which lay on a bench nearby. "They insulated me from the current and partially protected me from the sound. Though the force was very great, great enough to penetrate my insulation, it was handicapped in my case because of the garments." "I see. Well, you may go on." Phillips moved in the chair he had taken, from time to time. He could hear the noises of his men, still searching the premises for Madge Crawford, and Professor Lambert heard them, too. "Will you tell your men to be quiet?" he cried at last.