 In "Heretics of Dune" (1984), Hesterion is Archivist counselor and advisor to Mother Superior Taraza and one of the few sisters with access to sensitive breeding records.Hesterion is the first advisor to suggest that the Tleilaxu ambition is to produce a complete prana-bindu mimic, and she is correct.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.