"Where am I?" he demanded. His gaze roved the cave and fell on the President. "Hello, Robert," he exclaimed. "What has happened?" With a cry of joy the President sprang forward and wrung the hand of the man. "Are you all right, William?" he asked anxiously. "Do you feel perfectly normal?" "Of course I do. My neck feels a little stiff. What are you talking about? Why shouldn't I feel normal? How did I get here?" "Take him outside, Admiral, and explain to him," said the President. Admiral Clay led the puzzled man outside and the President turned to Dr. Bird. "Doctor," he said, "I need not tell you that I again add my personal gratitude to the gratitude of a nation which would be yours, could the miracles you work be told off. If there is ever any way that can serve you, either personally or officially, do not hesitate to ask. The other victims will be brought here to-day. Will you be able to restore them?" "I will, Mr. President. From Slavatsky's records I find that I will have enough if I reduce all of his men to a state of imbecility except Willis. In view of his assistance, I propose to leave him with enough menthium to give him the intelligence of an ordinary schoolboy." "I quite approve of that," said the President as Willis humbly expressed his gratitude. "Have you had time to make an examination of that ship of Slavatsky's, yet?" "I have not. As soon as the work of restoration is completed, I will go over it, and when I master the principles I will be glad to take them up with the Army-Navy General Board." "Thank you, Doctor," said the President. He shook hands heartily and left the cave. Carnes turned and looked at the Doctor. "Will you answer a question, Doctor?" he asked. "Ever since this case started, I have been wondering at your extraordinary powers. You have ordered the army, the navy, the department of justice and everyone else around as though you were an absolute monarch. I know the President was behind you, but what puzzles me is how he came to be so vitally interested in the case." Dr. Bird smiled quizzically at the detective. "Even the secret service doesn't know everything," he said. "Evidently you didn't recognize the man whose memory I restored. Besides being one of the most brilliant corporation executives in the country, he has another unique distinction. He happens to be the only brother of the President of the United States." [Advertisement: ] The Invisible Death A COMPLETE NOVELETTE _By Victor Rousseau_ [Illustration: Far overhead a luminous shape appeared.] [Sidenote: With night-rays and darkness-antidote America strikes back at the terrific and destructive Invisible Empire.] CHAPTER I _Out of the Hangman's Hands_ "You speak," said Von Kettler, jeering, "as if you really believed that you had the power of life and death over me."