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.

Prophecy season one, episode three, "Sisterhood Above All," the series shows us flashbacks of Valya and Tula Harkonnen's past.

Episode three of Dune: Prophecy looks back at Valya and Tula's past, providing the show's richest character drama yet.

Sisterhood above all” is the mantra. And it’s not like the Harkonnen sisters don’t believe in it. But Tula has her own agenda, too, just like Valya. They are aligned in their ongoing purpose, one that will combine their personal aims with the Imperium-maneuvering machinations of the reverend mothers.

The Sisterhood. The sisterhood in question refers to the manipulative nuns known as Truthsayers, but it could just as easily refer to the two most important characters in the show: Valya and Tula Harkonnen.