Unfortunately, no such change in tactics occurs in "The High-Handed Enemy." Written by Elizabeth Padden & Suzanne Wrubel and directed by Anna Foerster, the season finale squanders its potential to achieve actual compelling drama by favoring exposition and lore.
Nowhere is that more clear than in Lila's storyline. Chloe Lea has been a highlight of the series, especially when her wide-eyed true believer character accessed genetic memory and was possessed by her ancestors Dorotea (Camilla Beeput) and Raquella Berto-Anirul (Cathy Tyson). Lea convincingly plays a vengeful adult in the body of a child, and while the explanation of the mix of identities likely confuse viewers who have only seen the Denis Villeneuve movies, the composite character has a legible motivation. Valya killed Dorotea, and now Dorotea's back for revenge.
The episode starts to follow that trajectory, with thrilling scenes of Lila convincing her sisters to go along with her, before they realize that she's possessed by ancestors. But instead of having Lila go after Valya, she instead gets ideological. Lila spends all of her time gathering sisters to her anti-machine perspective.
The ideological turn in the episode fails for numerous reasons. First, it's just not as emotionally immediate as a revenge plot. Second, the philosophical stakes of the Butlerian Jihad haven't been well-articulated throughout the series. The show has demonstrated people mistrust machines in this world, but the religious fervor that drives Butlerians in the book has not been on display, not so much that it deserves this much attention in the finale, especially over a basic revenge plot. Third, it muddles Valya's intentions, which already fluctuates between revenge against the Atreides and putting a Sister on the throne.
Sadly, Lila's storyline is not the only time the finale chooses lore over characters. An otherwise powerful scene at the beginning, in which former Sister and current Suk doctor Nazir (Karima McAdams) exposes herself to the virus with Tula's help, trips up with they throw out the term "prana-bindu" as if it means anything to anyone who hasn't read the books. Furthermore, the duo discusses at length the virus's attraction to fear, which readers will recognize as setting up an origin for the Litany Against Fear, but doesn't feel like a actual conversation between real people.
The failure of the scene between Nazir and Tula highlights the true problem with this series. McAdams and Olivia Williams give proper performances during the interaction, doing their best to find emotional truth under all the jargon. Likewise, Jessica Barden and Emma Canning shine during a flashback scene with young Valya and Tula. Both performers use their expressive faces to speak volumes with just a wrinkled brow or a flicker in the corner of their mouths. In those moments, we believe that we're watching two sisters struggle with contradictory feelings and not just "pieces on the board," to use a tired metaphor invoked throughout the show.
Watson suffers worst of all in this regard. Not only has the writing on the series failed an actor of her caliber, but the adult Valya must be in control at all time, which deprives her of any opportunity to play the emotional range given to her on-screen sister Williams. The viewer can almost see Watson giving up on the character when Valya explains the entire plot of the show to Javicco, even as Mark Strong continues to play against type as the weak-willed Emperor.