The Imperium is changing. The first Emperor of the new dynasty walked into the desert to die. To the Imperium he is dead. His younger sister, Alia, has been regent for nine years for Muad'dib's twins, Leto II and Ghanima. The old ways are changing. Stillsuits are not necessary to walk out in the open. Water discipline is lax. The planet Arrakis is changing. Rain had fallen on the belt of Dune. Fremen have learned what it means to drown, what a flood is and there is open water, gardens, and orchards. The desert is receding and the sandworms are threatened along with the Spice. Alia had married Paul's swordmaster, the ghola Duncan Idaho. Alia, Leto II, and Ghanima were all preborn and Leto and Ghanima fear becoming possessed by the personalities within their consciousness, they see it already in their aunt Alia who is being slowly overcome by the evil Baron Harkonnen, her maternal grandfather. The twins fear their own power. As they are being groomed to rule the Empire, one of the Corrino daughters, Wensicia, grooms her own son, Farad'n, to take her father's throne. Everything comes to a head when Jessica, grandmother to the twins, returns to Arrakis from her self-imposed exile on Caladan. Has she returned to betray her own daughter, to bring her down? To groom the twins? To destroy the twins? Or to mate them for the Bene Gesserit's purposes? No matter her true purposes, her appearance on Dune has set plans in motion. But the Fremen do not believe Duncan Idaho's revelations. He must make a choice that may go against his loyalty and/or kill him. Meanwhile, there are those who believe the mysterious desert mystic known as The Preacher may be Paul Atreides back from the dead.