Dampier answered. "Many things, Monsieur. If you will watch--?" He pulled up his coat-sleeve, baring his scrawny arm, and clambering up on the platform pushed his hand and arm into the shining sphere. I saw the sweat come out on his forehead with the effort. Already the zone was strong. He withdrew his hand and touched the dials of the control-board. Nebel's eyes were watching every move, his hand in the pocket of his coat. Dampier stepped back. "If the gentlemen will shoot? But I warn you--be wary of the ricochet." Nebel's finger jerked up. "Rudolf!" The youngest of the three men stepped forward and emptied his gun at the shining globe. The first bullet passed through and spanged against the farther wall; the rest glanced whining from its surface and bit ugly scars from the concrete wall beyond. Dampier's eyebrows raised ever so little. "You have improved the quality of your guns," he commended. "They are more powerful than I had thought." "Is that all?" "Is it not enough? What weapon have your thieving swine stolen that will penetrate what you have seen?" "Is that all?" Nebel's face was purple with rage. They hated each other bitterly, these two, and Dampier had given him not the slightest satisfaction as yet. The Frenchman shrugged. "It is not complete. Nothing can pass the completed zone, though it is good enough now for anything your blundering fools have invented or will invent. However--" He turned to the dials. Then suddenly he wheeled. His thin lips were drawn back in a snarl of fury, his eyes were sunken pools of black hate. With a scream he leapt at Nebel's throat. The first slug caught him in mid-air. The shock dropped him in a crooked heap. Five more bullets smacked into him as he lay there, then Nebel's polished shoe went out and turned him over on his back. He lay there, a bloody froth on his contorted lips, sneering up at the man who had killed him. For the first time Nebel turned to me. "It was in self defense. You will remember that, Mr. Crandall, if I decide to let you live." He went to the machine, as Dampier had done, and tapped the dials lightly with his long white fingers. "These red marks--they are, I suppose, the settings with which Monsieur Dampier was working. He would not go beyond, for me. And yet, they are less than halfway to the limit of the dials. What will happen, if I turn them so--a hair beyond?" His fingers twisted once, twice, and behind us Bill Porter's voice cried out. "Stop, you fool! Stop!" He stood in the door of the temperature room, the sheaf of Dampier's notes in his hand. Nebel's thin eyebrows went up. "Mr. Porter! I had forgotten you. And why am I a fool?" His fingers spun another of the dials. "You murdering Teuton fool!" Bill's tone was venomous. "What do you know about science? Your agents bring you this and that. You pay them or kill them, as may be convenient, but what do you know or care about what they have given you, so long as it can be sold at a profit: Mike, come here."