On the planet Lankiveil, the Harkonnen family ekes out a lean existence, far from the glory enjoyed by their ancestors after Vorian Atreides disowned the disgraced ]Abulurd Harkonnen. While the parents have decided to surrender ambition for survival and a humble existence, the two oldest children, Griffin and Valya, seek to rebuild their family fortunes through service to the Landsraad and the Sisterhood on Rossak, respectively.
Vorian's granddaughter Raquella Berto-Anirul, who survived a poisoning that provided her with the memories and mental presences of her female ancestors, leads the Sisterhood of Rossak. She thwarts Butlerian sympathizers within her own ranks, who correctly suspect that Raquella and her inner circle are using computers to manage their breeding index, which comprises an immense amount of family data from across the Imperium. Raquella is aided in these efforts by Sister Valya Harkonnen, who finds her efforts to rebuild her family's glory impeded when the spoiled Princess Anna Corrino (sister to Emperor Salvador and Roderick) is sent to Rossak. Anna, viewed as an embarrassment by the royal family, is meant to learn important skills with the Sisters, but instead follows her own childish ambitions.
Sister Dorotea steals two pills of the Rossak drug that gave Raquella her abilities and encourages Valya to take it alongside her. While Dorotea became the second ever Reverend Mother after taking and surviving it, Valya merely pretends to take it, but keeps the pill. Reverend Mother Dorotea learns of the Sisterhood’s secret computers, and that Raquella is her grandmother. More follow her; including Anna Corrino, who fails to become a Reverend Mother and enters a trance state. Through the new director of the Suk Medical School (and former Rossak Sister) Dr. Ori Zhoma, the Sisterhood also plots against Salvador, who it fears may be the ancestor of a potentially disastrous tyrant.
