'Dune: Prophecy' star Chloe Lea details filming 'terrifying' Agony moment in HBO show

As the origin story of the Bene Gesserit continues in Dune: Prophecy (streaming on Crave in Canada, Max in the U.S.), Lila, played by Chloe Lea, has a particularly impactful moment, undergoing a ritual so Valya Harkonnen (Emily Watson) can gather more information about Mother Raquella's prophecy. Lila is Raquella's great-great granddaughter, and while Tula (Olivia Williams) feels particularly close to Lila, Tula must have the acolyte go through the Agony, a version of what Paul Atreides and Lady Jessica undergo in the Dune films, taking poison to unlock "genetic memory."

This scene brought a particular anxiousness to the story, as Lila is met with figures of her ancestors and the unexpected appearance of her dead grandmother Dorotea, seeking revenge after Valya killed her decades earlier, which leads to Lila's death. But for Lea, that moment for Lila felt "relatable."

"Lila kind of trying to figure out who she is, ... where she came from and [the impacts] her ancestors had on her, I feel like that part I really related to on just a human level," Lea said. "But then there's obviously the other side of it, which is very Frank Herbert-y, very Sisterhood-y with the whole interaction with her foremothers."

"It kind of feels like that part of the episode is quite ... charged with the horror genre. So it was kind of making sure that it remained grounded as much as it could, because I feel like it's very easy to get carried away with that type of imagery, because it's just so terrifying. It was very liberating to be able to go to those places as an actor, because it's stuff that you don't usually get to tap into."

'She has developed a relationship that probably the Sisterhood would disapprove of'

In portraying the relationship between Tula and Lila, Olivia Williams stayed true to the reality of someone in a powerful cult, with Tula needing to follow her sister's instruction, but also really caring about Lila and wanting the best for her.

"One of those dreadful things that belonging to a powerful cult does to you, it stops you from forming loving relationships, or breaks the loving relationships you have, and at some point will ask you to destroy them," Williams said. "And that is the dilemma that she's put into."

"There are other examples that I've seen in my life of people joining a cult that asks them to break with their family or do something that they would not instinctively want to do. And it's a heartbreaking moment for Tula, because she has developed a relationship that probably the Sisterhood would disapprove of, of feeling motherly towards Lila and wanting to pick out a favourite."

The actor also spoke to her mother, who went to a Catholic convent, and found similarities in that experience.

"I did talk to my mum, who actually went to a quite a strict Catholic convent, and she said there were the nuns who sort of chose a child, and there were nuns who fell in love with another child, and there were those who would just pick on an individual who they thought was an evil sinner and a representative of the devil," Williams shared. "That's what happens when you cloister people and create unnatural deprivation emotionally, I think."

'The audience gets to decide who they root for'

While this is happening in Dune: Prophecy, Valya has taken Theodosia (Jade Anouka) under her wing, bringing her on a trip to the imperial capital with the instruction to become a close ally for Princess Ynez (Sarah-Sofie Boussnina), meaning Theodosia has been forced to leave the other Sisterhood trainees.

"It was quite similar, life, art, because I had been with the girls in the Sisterhood, we'd been training together. We'd spent a long time working on all the different training that actually the characters go through," Jade Anouka said. "And then suddenly Valya comes and says, 'You're leaving them, you're coming with me on your own.'"

"The character's a bit like, 'oh,' ... because ... this was a safe space to be, and now you're taking me out of that. And practically as well, suddenly I wasn't working with these guys. I was off with Emily. But then it was amazing, because I got to work with Emily. ... But it was very similar to being away from the safety net."

But as the actor highlighted, a strength of this series moving forward will be that "allegiances change."

"It feels like they're constantly changing, and who you think is good and who you think is bad is constantly changing," Anouka said.

"The audience gets to decide who they root for," Lea added. "It's not this black and white story where people are being pushed to decide that someone is good, so they must be on their side. I think it's up to the audience's perspective."