Chapterhouse Dune recap

Cornered by the Honored Matres, the Bene Gesserit, led by Mother Superior Darwi Odrade, gamble everything on turning the tables. On their hidden homeworld of Chapterhouse they nurture new sandworms from the single worm rescued earlier, working to secure the spice supply as the enemy destroys sisterhood strongholds one by one. Odrade has the great Bashar Miles Teg revived as a ghola child and his memories restored, betting on his military genius. She also pushes Murbella, the Honored Matre bonded to the Duncan Idaho ghola, through full Bene Gesserit training, planning to unite the two rival sisterhoods under one leader. Odrade leads a bold, personally dangerous mission to the Honored Matre stronghold to confront their supreme ruler. In the decisive clash, the Honored Matre leadership is broken and Murbella kills their supreme commander, taking control of both orders and beginning to merge them, though many Bene Gesserit distrust the union. Odrade dies, first passing her memories to Murbella and Sheeana. Fearing Murbella's new regime and a shadowy, greater enemy that first drove the Honored Matres out of the Scattering, Duncan, Sheeana, the child Teg, the captive Tleilaxu Master Scytale, and others slip away in a cloaked no-ship into unknown space. The series closes with their escape unresolved, pursued in the distance by a mysterious old man and woman whose true nature is never revealed.

Previously in the Dune series: for thousands of years the desert planet and its spice shaped human destiny. Paul Atreides rose as the messiah Muad'Dib and took the throne; his son Leto II became an immortal, worm-bodied God Emperor who ruled for three and a half millennia to force humanity onto a survival course called the Golden Path. His engineered death shattered his tyranny and sent great waves of people fleeing into unknown space in the Scattering, while famine and collapse gripped the old empire. Fifteen centuries later, the disciplined sisterhood of the Bene Gesserit had become the quiet power among the stars, aided by the Tleilaxu, who could grow living copies of the dead. Then a terror returned from the Scattering: the Honored Matres, a matriarchy that conquers through overwhelming violence and sexual enslavement. In the previous volume, Heretics of Dune, the Honored Matres destroyed the desert planet Rakis and its sandworms. The Bene Gesserit escaped with one captured worm, the means to grow more, a revived ghola of the ancient swordmaster Duncan Idaho, and Murbella, a defecting Honored Matre bonded to Duncan, but they lost their great commander, Miles Teg, and countless of their own. Now the sisterhood shelters on its secret homeworld, Chapterhouse, transforming the planet into a new desert to breed sandworms and preserve the spice, while the Honored Matres hunt them across the galaxy in a war the sisters are steadily losing.

The saga's final volume ends without full resolution, as its author left the story open. Cornered by the conquering Honored Matres, the Bene Gesserit under Mother Superior Darwi Odrade stake everything on a plan to absorb their enemy rather than merely defeat them. On their homeworld of Chapterhouse they breed new sandworms to secure the spice, revive the master strategist Miles Teg as a ghola, and drive the defector Murbella, bonded to the Duncan Idaho ghola, through complete Bene Gesserit training so that she might lead both sisterhoods at once. Odrade takes a great personal risk in a mission to the Honored Matre capital to confront their supreme leader. In the climactic confrontation the Honored Matre command is broken and Murbella slays their ruler, seizing authority over both orders and beginning to fuse them into one, though many of the old sisters remain wary of a leader with an Honored Matre's past. Odrade is killed, but not before sharing her lifetime of memories with Murbella and Sheeana so the sisterhood's essence survives. Distrustful of Murbella's merged order, and wary of a far greater unknown power whose pursuit had driven the Honored Matres back from the Scattering in the first place, a small group escapes: the Duncan ghola, the sandworm-commander Sheeana, the child Teg, the imprisoned Tleilaxu Master Scytale, and their companions flee in a hidden no-ship into uncharted space. They are shadowed by a strange, seemingly all-powerful old man and woman whose identity is never explained, and the series ends with the fugitives' fate, and the ultimate threat, left unresolved.