Suddenly a wild-eyed seaman sprang at my throat. In spite of my amazement, I was able to stop him with a punch at the jaw. In a moment I realized what he was after. The parachute that I had worn on my last flight in the Camel-back was strapped to me. As the fellow got up to charge again, the deck tilted (probably the ship was upset by the recoil of the gun). Presently I found the rip-cord and jerked it. The white silk bellowsed out behind me, while my unfortunate shipmates fell, dwindling dark specks, to make white splashes in the sea below. The ill-fated ship must have been half a mile high then. I glimpsed it once or twice, a vanishing black dot--driven out into space! By the time I had struck the chill water I almost wished that I had fallen with the others. I contrived to cut the harness loose, and to get rid of my coat and shoes; and set myself to the task of keeping afloat as long as possible. On to the Mine It must have been an hour later that I heard the hum of the Camel-back's propeller, and saw the little machine skimming low over the waves. Bill leaned out and waved a hand in greeting. In a few minutes he had brought the machine down lightly in the water beside me, and hauled me aboard. "I went up at three o'clock," he said, "to see if I could locate the Jap. I was coming down when the red machines began to let loose their shining clouds. The plane went up. I stopped the engine, and still it went up. Its weight was gone. I almost froze before it started falling." "Those ships may go on to the moon! They may become minor satellites themselves!" "You saw the red machines dealing out the dope?" "One of them. Who could it--" "It's our job to find out. We better head back for the mine, to see what's happened there." The trim little machine skimmed smoothly over the level sea, and easily took the air. We flew southwest. It was not many hours before we sighted land that must have been the lower tip of Lower California. In an hour more we were flying over Mexico, the most ancient, and paradoxically, the least known country on the continent. We flew over a broad plain checkered with the bright green of fields, over ancient cities and mean adobe villages, and over the vast forests of pine, cut with twisting canyons, that cover the slopes of the mighty mountains that rose before us. As we went on, the green valleys of the rushing mountain streams grew narrower; and the grim wild peaks that rimmed them, higher and more frequent. Sheer jagged summits rose above steep, forest-covered slopes. We were reaching the heart of the Sierra Madre range. At last the vast bare conical mountain loomed up to the north of us, that Bill told me was Mocolynatal--the place of the hidden radio station. Its sheer black slopes tower fifteen thousand feet above the sea. From its appearance, it was not hard to guess that it had a crater of considerable dimensions.