Gotch spoke: "We know you're Captain Rennell, sir. And this gentleman, we know him too, but he seems a bit queer in his head. Talking of the Invisible Emperor's headquarters on this island, a mile or so inland. The only invisible thing we've found is that piece of a garment we pulled off you." "I broke my watch ray machine in the fall, and I can't make them believe, Rennell," almost wept old Evans. "Tell them I'm not crazy." Dick got upon his feet with an effort, staggered a little, then made his way to Fredegonde. He kneeled down beside the girl. She was conscious, and smiled faintly, but she could not speak. He pressed her hand, rose, and came back. "Mr. Evans is not crazy," he said. "The headquarters of the gang is over there." He pointed. "Didn't President Hargreaves tell you?" "He was kind of incoherent, sir." The marines looked at one another, wondering. Was Captain Rennell crazy too? "We've had scouts out through the jungle, sir. There's nothing within five miles of here. They had a clear view through to the sea from the top of a hill." "I've been there." Dick spoke with conviction. "I must tell you they've got devices that make them practically irresistible. That gas and other things. And they're invisible. But if you boys are willing to follow me, I'll lead you. It means death. I don't know what they're waiting for. But--are you willing to follow me?" "We'll follow you, sir"--after a pause, during which Dick read in their eyes the desire to humor a crazy man. "We'll follow to hell, sir--if that gang's really there." "Take your arms, then!" Dick pointed to the stacked rifles. A minute later the twenty-odd Marines, forming an open line that extended from one side of the clearing to the other, were on their way toward the headquarters of the gang. And Dick, leading them, though his head was reeling, felt as if his own reason was slipping from him. Had he only dreamed all this? Was it possible that the headquarters of the Invisible Emperor existed on this desolate prairie? If it was true, why had they suddenly become silent, inert? Why had they not long ago wiped out these few Marines? And the gale--was it now sweeping northward on its mission of destruction? * * * * * Half an hour passed. Then the brown patches of the foundations came into view upon the open ground. Here were the hangers, here was the central building with the Emperor's headquarters. And nothing was visible, nothing stirred, yet at any moment Dick expected the rattle of machine-gun bullets or some more terrific method of destruction. "Halt!" The line stood still. "I am going forward ahead or you. You'll follow at a distance of twenty paces. When you see me stop, feel for the door in the wall, and if I disappear, follow me. You understand?"