“You knew Dr. Heidenmuller,” I said abruptly. “Yes, poor old chap,” he said calmly. “How did you happen to run across him?” “I didn’t know him personally,” I said, “but I knew a man who did know him. One of our own men, Tom Haldane of Columbia, who is very greatly interested in the radio-active work which Dr. Heidenmuller was carrying on before his death, is here with me.” Hamerly’s face filled with eagerness. His whole attitude changed. “Did Haldane know what he was doing?” he asked breathlessly. “Not exactly,” I said. “Well if he knows anything about it, I believe he knows one of the greatest things in modern science. The Doctor never told me anything about it, but I went into that room the day he was taken out dead, and ever since that time I’ve felt that he had found a force greater than anything yet obtained, and that that force killed him.” He paused. “I’ve never said that to anybody else, but Haldane is the man of all others to know it, and you might tell him that from me. He may be able to use it somehow. I can’t. I tried my best to get hold of some clue concerning it after Heidenmuller’s death, but it was absolutely useless. Do you think that Haldane has enough data to work it out?” “Frankly, I don’t know,” I said. “Except for two things, I should have said the secret died with him,” said Hamerly slowly. I bent forward hanging on every word. “I’ve never spoken of either, but,”--he paused, “you know this man who is trying to stop all war?” I nodded. “Well, from the way Heidenmuller’s room looked, and the way the things in his pockets were left, I’ve wondered if the man had not his secrets. Do you know,” he said, leaning forward, “there were no eyelets in his shoes when he was found. The crimps were in the leather of the strings, but the metal ends were gone. The lenses of his spectacles, without any mounting, were lying on the floor. The very filling of his teeth had gone. Why couldn’t a battleship disappear into its elemental parts the same way, all its living contents paralyzed by the shock, dying instantly and sinking below the waves. I’ve wondered more than once if the government sent down divers in Portsmouth harbor and if they did, what they found.” There was just one thing to do. He held as much as we did of the secret. Perhaps he knew more. From beginning to end, I told the whole story of our search. As I went on, he grew more and more excited. As I paused towards the end, he broke in. “The second thing fits in here, the reason why I believe the secret might not be lost. One day as I went into the laboratory, the Doctor’s assistant told me that he was in the inner room, but had left word for me to wait. I was extremely curious for no one had ever entered that inner room to my knowledge. The door opened at last, and a tall, dark man, an American I should say, came out of that closed room with the doctor. I never saw him before or since. Now, is he the man who got the secret, and with it is trying to stop all war?”