There had been very little said, naturally. Petley had broken the rules in turning a ship over to a boot, in the first place; and one of the other trainees had saved them by seizing the controls at the crucial moment and decelerating. Dirk had asked to be transferred to another class, and his request was granted. He was, after all, the Commandant's son and allowances must be made. Enough allowances were made to permit him to graduate from the strato-school. He was a great theorist, his instructors agreed. Perhaps he lacked a little of his father's daring and drive, but he had the same comprehension, the same inter-stellar grasp. And after graduation, nothing sensational. A little routine work between Mars and Luna--work which permitted him to stay in the navigator's cell--away from the visi-shield--away from the twisting whirlpool of space. For, after all, promotions must not come too rapidly. He was the son of a famous man and sons of famous men are closely observed by the Universe. When he rose, it must not be the result of family, but because he was well qualified and experienced. * * * * * His days as a Lunar navigator were as happy as any Dirk had known, but they were not to last. Commandant Jemson was planning another voyage of exploration--the most audacious in his long and brilliant career. The goal was the dark satellite known as Caliban. A space armada would accompany the commandant on this, the climactic space trek of his colorful career, and in charge of one cruiser in the fleet would be Dirk Jemson--the commandant's brilliant but untried son. And now, they were approaching Caliban. "What d'ya think we'll find on Caliban, Doc?" Kennedy addressed his question to Tabor, who had closed his book with a little sigh, and was staring dreamily ahead. "Very little." Tabor pursed his lips in an academic pout. "It is my theory that the atmosphere on Caliban will not support organic life as we know it." "But there could be other kinds? Like the Venusians, maybe, or those things from Circe I've seen at the Zoo." Tabor nodded. "That's what makes being a part of this expedition so stimulating. When we reach Caliban, I will be the first biophysicist to be permitted to examine the satellite. I'll be the first to coordinate fact and theory." Allen peered through the visi-shield. "You can start coordinatin' pretty soon, Doc. Caliban's just ahead." As Allen spoke, the audio-visor above his head hummed and flickered. Dirk tensed himself. This was it. In a few seconds, that humming and flickering would materialize and he would be watching his father's face, hearing his father's voice. As with a single impulse, the other three men in the cabin turned and regarded Dirk. They seemed to sense that the moment was his. Allen stepped back from the visi-shield; Kennedy turned from his gauges.