The ball hung free in space, supported by the magnetic attraction of the curved bars that made a cage about it. An adaptation of the electrol device that had appeared on the most modern ships, Harkness knew how to handle it. Each movement of the ball within its cage, where magnetic fields crossed and recrossed, would bring instant response. To lift the ball would be to lift the ship; a forward pressure would throw their stern exhaust into roaring life that would hurl them forward; a circular motion would roll them over and over. It was as if he held the ship itself within his hand. Chet touched a button, and a white light flashed to confirm his report that all was clear. Harkness gently raised the metal ball. Beneath them a soft thunder echoed from the field of snow, and came back faintly from icy peaks. The snow and ice fell softly away as they rose. A forward pressure upon the ball, and a louder roaring answered from the stern. A needle quivered and swung over on a dial as their speed increased. Beneath them was a blur of whirling white; ahead was an upthrust mountain range upon which they were driving. And Harkness thrilled with the sense of power that his fingers held as he gently raised the ball and nosed the ship upward in meteor-flight. The floor beneath them swung with their change of pace. Without it, they would have been thrown against the wall at their backs. The clouds that had been above them lay dead ahead; the ship was pointing straight upward. It flashed silently into the banks of gray, through them, and out into clear air above. And always the quivering needle crept up to new marks of speed, while their altimeter marked off the passing levels. * * * * * They were through the repelling area when Harkness relinquished the controls to Chet. The metal ball hung unmoving; it would hold automatically to the direction and speed that had been established. The hand of the master-pilot found it quickly. They were in dangerous territory now--a vast void under a ceiling of black, star-specked space. No writhing, darting wraith-forms caught the rays of the distant sun. Their way seemed clear. Harkness' eyes were straining ahead, searching for serpent forms, when the small cone beside him hummed a warning that they were not alone. Another ship in this zone of danger?--it seemed incredible. But more incredible was the scream that rang shrilly from the cone. "Help! Oh, help me!" a feminine voice implored. Harkness sprang for the instrument where the voice was calling. "We aren't the only fools up here," he exclaimed; "and that's a woman's voice, too!" He pressed a button, and a needle swung instantly to point the direction whence the radio waves were coming. "Hard a-port!" he ordered. "Ten degrees, and hold her level. No--two points down."