In this third installment, "Sisterhood Above All," we begin with a shellshocked Valya exiting the palace gates on Salusa Secundus with Sister Theodosia. Fearing that the Sisterhood's hold on the great houses is quickly slipping, they must act fast to regain control, especially with the Emperor's House Corrino.

Dune: Prophecy takes a deep dive into the lives of Valya and Tula Harkonnen, ending with a sequence where Valya visits her uncle and nephew. Actors Emily Watson and Jessica Barden play Valya Harkonnen,

Sisterhood above all” is the motto of Valya and Tula’s secretive organization, but its meaning seems to depend on which sister is saying it.