The blood feud between Duke Leto of Caladon and Baron Vladimir Harkonnen reaches its climax, as the emperor Shaddam - leader of House Corrino - is finally forced to curb the powerful Harkonnens or risk losing his own throne. Menawhile, Duke Leto's beautiful concubie, the Bene Gesserit temptress Jessica, - has conceived the boy who become Paul Atreides (the hero of Dune), defying the express orders of her superiors. The book culminates in a war - on Dune, on the oppressed planet Ix, in space - that will alter the balance of power for a generation.