Some years hence there is rebellion among the colonists on Titan, a Saturn moon, who are mining ruthenium, a valuable catalyst in the process of converting solar heat into power. Earth security agent Col. Benedict and his son Dave are sent to discover and check the activities of the suspicious Titan leader Anson Torm. They find instead, that Torm wants only recognition and a decent status for his people in the solar system and is himself fighting another upstart, Cortell. Dave and his father help, and in adventures which Mr. Nourse weaves pretty well into what is actually known of Titan and its atmosphere, the colonists gain new footing and are able to start yet another venture, the first trip to the next solar system. Not bad.