Iriel is tasked to cultivate the Cult of Sheeana on Gammu; in Hunters of Dune (2006), she discovers the Honored Matre plan to send Obliterators on a Spacing Guild heighliner to destroy Chapterhouse. She and some of her followers barely escape Gammu with their lives, but manage to reach Chapterhouse and warn Murbella in time. Soon after, Iriel is killed in the Bene Gesserit takeover of Gammu.
Read more about this topic: List Of Dune Bene Gesserit