The rocket ship whirled down from the sky and crashed into the hillside. A cloud of dust rose lazily from the spot and mingled with the white fumes escaping from the vessel. The escape hatch opened and Archie Simms jumped down to the surface of the planet. "Oh-oh, Ed—here's the welcoming committee!" he yelled. Ed Bailey's face appeared in the doorway. The two men stared grimly at a motionless purple sphere, about eight feet in diameter, that rested fifty feet from the damaged rocket. On the surf