Shaved and freshly clothed, Frenchy Logrieux was handsome in a dark furtive way. His gallantry and thinly veiled compliments seemed to amuse Alyce Marshall, yet they drove Rufus Thallin into a silent fury. He resolved that the space-flyer would leave Cerberus without Frenchy Logrieux, and that was all there was to it. He needed a fresh water supply for the space-flyer. It had landed in a big valley of tremendous naked rocks. Each night it rained on Cerberus and the water flowed into a large crystal pool at the other end of the valley. Frenchy showed him a path leading down to the water. "Ought to do, after it's distilled," commented Rufus, bending over to examine the chemical rings deposited on the rock by higher water levels. It was Frenchy's opportunity. Rufus saw the swart features in the pool's reflection, then felt the shock of a blow that hurled him down into the deep pool. He sank swiftly, for the water was not as heavy as that of earth. Long arms pumped like pistons, stirring up filmy clouds of white silt from the submarine floor. But he quit struggling. No use trying to swim in that thin fluid. He'd have to climb! Lungs near to bursting, he jammed his hands into the crevices of the precipitous walls and began to pull upward. His fingers tore on knife-edged formations of lime and silicate, leaving crimson smears in the water below, but he kept climbing. At last his head broke water and he gulped in precious lungfuls of rarefied atmosphere. Frenchy Logrieux was nowhere in sight. The thin air was being split by a clap of thunder. Rocket blasts! Dripping water, he lurched up along the trail, his bleeding fists clenched at his sides. Young Rufus Thallin had cast off his exhaustion with his first few lungfuls of air, and as he raced up the broken trail of glassen fragments his grim face became as dark as a thundercloud. He saw the space-flyer, cushioned on its jets of rocket blasts, could make out Frenchy's dark face hovered over the controls. Then the flames died away with a final swoosh and the space cruiser settled. The pirate was fighting the controls insanely, his nervous fingers flying everywhere in an effort to get a response from the rockets. Rufus darted across the blackened rock, still warm from those first flame spurts, and his big fingers searched deftly along the outer rim of the airlock. Both the inner and outer doors of the airlock slammed open. The girl was lying on the bed, her arms and legs having been bound hurriedly from strips of her torn skirt. Now he halted in the doorway, shouted for the pirate to come out. "I've got a gun, Frenchy!" he yelled. "Come out with your flippers in the air, if you want to live! You didn't think I'd leave the space-flyer so you could run it, did you?"