A few years after the truce between the Union and the Alliance factions, Union lands a new settlement on the world called Gehenna, a colony consisting of 41,911 "non-citizen" clones and several hundred natural born men as supervisors. Gehenna seemed to have no intelligent native life-and therein lay the mistake. Calibans, dragon-like beasts, had a different sort of intelligence; and, as time passed, they began to twist the minds of the new generations to their own inhuman rhythms of life. Abandoned as a colony, life on Gehenna assumed stranger and stranger forms-until the day that Alliance spies arrived and applied the match to the many social explosives that had been piling up.