Dune Messiah recap

Twelve years after seizing the throne, Paul Muad'Dib rules as Emperor while the holy war waged in his name has killed billions across the galaxy. A conspiracy forms against him, drawing in the Spacing Guild, the Bene Gesserit sisterhood, the shapeshifting Bene Tleilax, and his unloved wife Irulan. The Tleilaxu present Paul with a ghola, Hayt, grown from the corpse of his dead swordmaster Duncan Idaho and secretly conditioned to strike at him. The plotters use a forbidden weapon, a stone burner, whose radiation destroys Paul's eyes, though his prescience lets him move as if he can still see. Chani, denied children by Irulan's hidden sabotage, finally conceives, but she dies bearing twins, Leto and Ghanima. Confronted by the conspirators, Paul resists the temptation to trade his rule for a Tleilaxu offer to restore Chani; Hayt's buried identity as Duncan reasserts itself, breaking his conditioning, and he kills the agent Scytale. When his prescient sight fails at last, the now truly blind Paul follows the Fremen custom of walking alone into the desert to die, leaving his sister Alia and Duncan to rule as regents for his children.

Previously, in Dune: in the far future, the noble House Atreides is granted control of the desert planet Arrakis, the only source of the spice melange, a substance that extends life and makes interstellar travel possible. It is a trap. The rival House Harkonnen, backed secretly by the Padishah Emperor, destroys the Atreides and kills Duke Leto. His concubine, the Bene Gesserit Lady Jessica, and their teenage son Paul escape into the deep desert and are taken in by the Fremen, the planet's hardy native people. Exposure to spice awakens in Paul a terrible prescience, and he comes to be seen as the Fremen's long-prophesied messiah, taking the names Muad'Dib and Usul. Jessica becomes a Reverend Mother, and the ordeal that transforms her also awakens her unborn daughter, Alia, who is born already possessing adult awareness. Paul takes the Fremen woman Chani as his beloved. Leading the Fremen and their sandworm-riding warriors, Paul overthrows the Harkonnens and defeats the Emperor's forces, compelling Shaddam IV to abdicate. He seizes the imperial throne, marrying the Emperor's daughter Irulan to secure his claim while keeping Chani as his true love. But Paul foresees that his victory will unleash a fanatical holy war carried across the galaxy in his name, a bloody future he dreads yet cannot escape.

Paul's reign ends in loss. Blinded by the conspirators' stone burner, he continues to function through prescient vision alone, but the futures he sees close in around him. His beloved Chani, whose pregnancy had been secretly delayed by Irulan, dies giving birth to twins, a son and daughter named Leto and Ghanima, both born with the ancestral awareness of the pre-born. Grief-stricken, Paul confronts the Tleilaxu Face Dancer Scytale, who offers to recreate Chani as a ghola if Paul will surrender his throne. Paul is nearly broken by the temptation, but Hayt, the ghola of Duncan Idaho, throws off the murderous conditioning laid on him, recovers his true self, and kills Scytale, becoming fully Duncan again. Paul's inner sight finally gives out, leaving him wholly blind, and by Fremen law a blind man belongs to the desert. Refusing the diminished life his enemies would allow him, he walks out alone into the sand to die rather than cling to power. His sister Alia, a powerful young Reverend Mother, and the restored Duncan Idaho take up the regency, ruling the empire in the name of the infant twins. The failed conspirators are left to face judgment, and the future now rests on the two prescient children Paul has left behind.