Our ship moved ahead down a long slant, gradually dropping nearer to the ground. I watched the maneuver with interest while Jim, with his friend the beetle commander, went over the ship. The insect was evidently amused at Jim and was determined to find out the limits of his intelligence, for he pointed out various controls and motors of the ship and made elaborate sketches which Jim seemed to comprehend fairly well. * * * * * One of the beetles approached the control board and motioned me back. I stepped away from the board; evidently a port in the side of the vessel opened, for I felt a breath of air and could hear the hum of the city. I walked to the side and glanced down, and found that we were floating about twenty feet off the ground over a street on the edge of the city. On the street a short distance ahead of us two children, evidently returning from school, to judge by the books under their arms, were walking unsuspectingly along. A turn of the dial sped up our motors, and as the hum rang out in a louder key the children looked upward. Two of the long flexible wires shot out and wrapped themselves about the children; screaming, they were lifted into the space flyer. The port through which they came in shut with a clang and the ship rose rapidly into the air. The children were released from the wires which coiled themselves up on deck and the beetle who had operated them stepped forward and grasped the nearer of the children, a boy of about eleven, by the arm. He raised the boy, who was paralyzed with terror, up toward his head and gazed steadily into his eyes. Slowly the boy ceased struggling and became white and rigid. The beetle laid him on the deck and turned to the girl. Involuntarily I gave a shout and sprang forward, but Jim grasped me by the arm. "Keep quiet, you darned fool!" he cried. "We can do nothing now. Wait for a chance!" "We can't stand here and see murder done!" I protested. "It's not murder. Pete, those children aren't being hurt. They are being hypnotized so that they can be transported to Mercury." "Why are they taking them to Mercury?" I demanded. "As nearly as I can make out, there is a race of men up there who are subject to these beetles. This ship is radium propelled, and the men and women are the slaves who work in the radium mines. Of course the workers soon become sexless, but others are kept for breeding purposes to keep the race alive. Through generations of in-breeding, the stock is about played out and are getting too weak to be of much value. "The Mercurians have been studying the whole universe to find a race which will serve their purpose and they have chosen us to be the victims. When their fleet gets here, they plan to capture thousands of selected children and carry them to Mercury in order to infuse their blood into the decadent race of slaves they have. Those who are not suitable for breeding when they grow up will die as slaves in the radium mines."