Emily Watson and Shirley Henderson will lead the “Dune” prequel series at HBO Max. Watson and Henderson have been cast as Valya Harkonnen and Tula Harkonnen, described by the streamer as “the formidable Harkonnen Sisters, who have risen to power in the Sisterhood, a secret organization of women who will go on to become the Bene Gesserit.”The prequel series, titled “Dune: The Sisterhood,” is set 10,000 years before the ascension of Paul Atreides and follows the Harkonnen Sisters as they combat forces that threaten the future of humankind and establish the fabled sect known as the Bene Gesserit.The series is adapted from the novel “Sisterhood of Dune” by Brian Herbert and Kevin J.