The Bene Gesserit are under siege. The Honored Matres - a violent and mysterious faction that emerged from the Scattering - are systematically destroying Bene Gesserit planets, and Chapterhouse, the sisterhood's hidden homeworld, may be next. Mother Superior Darwi Odrade must forge an unprecedented strategy to save her order: transforming Chapterhouse itself into a new Arrakis by introducing sandworms to create a spice cycle, while simultaneously attempting to absorb and neutralise the Honored Matres rather than fight them. Chapterhouse: Dune is Frank Herbert's final novel, published the year before his death, and it ends on a deliberate cliffhanger - two characters fleeing into the unknown aboard a no-ship, with the nature of their pursuers left tantalizingly unresolved. It remains a powerful and unsettling conclusion to one of science fiction's greatest achievements.