Will Barrent finds himself, without memory of any crime or of his previous life, being shipped to the planet Omega. Used to imprison extreme offenders, Omega has a hierarchical society of extreme brutality, where the way to advance & avoid dying is to commit endless crimes. The average life expectancy from time of arrival is three years. The story concerns his attempt to survive, escape & return to Earth to clear himself of accusations against him.Earth is a uniform utopian society based on mutual trust & conformity. It's sleepy & stagnant, developing neither socially nor technologically. Its social stability is maintained by robots brainwashing children in closed classes. The ideologies of both Earth & Omega are similar, differing only in words. On Omega, the citizens worship Evil in a cult dedicated to an entity called The Black One. On Earth, the world religion is an amalgam of all the good aspects of previous religions. Its institution is the Church of the Spirit of Mankind Incarnate.As Barrent comes closer to the truth about the reason for his incarceration, his Omegan consciousness conflicts with his subconsciousness which was programmed in the closed classes by the robots during his childhood. The subsequent psychological struggle is played out by repeating all of the previous fights & battles which he experienced throughout the book, eventually making clear the vision which the mutant girl on Omega foresaw of his death.