Chapterhouse: Dune

Chapterhouse: Dune is the last novel Frank Herbert finished before his death in 1986. The Bene Gesserit, pushed out of Arrakis, attempt to recreate its ecology on their home planet while Mother Superior Darwi Odrade plans a final confrontation with the Honored Matres.

Herbert ended the novel on a cliffhanger that was resolved twenty years later by Hunters of Dune and Sandworms of Dune, built from his unpublished outline.