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.

Griffin Harkonnen, the only brother of Valya and Tula Harkonnen, makes a compelling introduction in Episode 3 of Dune: Prophecy. Once a powerful house, the Harkonnen family has been shunned by the Imperium and relegated to their home planet of Lankiveil, where they survive by harvesting whale fur.

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.