WARNING: The following contains spoilers from Sunday’s episode of Sharp Objects. Read at your own risk!

“That’s what I wanted to apologize for,” Adora (Patricia Clarkson) murmurs to her daughter, Camille (Amy Adams), in the latest episode of Sharp Objects, HBO’s adaptation of Gillian Flynn’s disturbing novel. “You can’t get close. That’s your father. And it’s why I think….” She pauses and looks at Camille with an expression that could almost be read as pity, before saying the four words that will lead Camille down a whole new, even darker spiral.

“I never loved you.”

It’s a chilling statement that left even Clarkson in awe as she said Adora’s words. “It’s something I don’t think anyone’s said before,” she told EW in May, after cryptically talking about the scene. “The journey this takes, where Amy and I begin is light years in [the finale] from where we’ve traveled. And what happens [in between] is…” — she trails off and sighs — “dark as hell.”

Below, the actress delves into what it’s been like playing Wind Gap’s mercurial, frosty leading lady.

Image zoom Anne Marie Fox/HBO

ENTERTAINMENT WEEKLY: Adora, much like her younger daughter Amma (Eliza Scanlen), adopts almost entirely different personalities depending on the situation. Adora’s ability to charm the entire town is on full display in this latest episode set on Calhoun Day. How have you thought about Adora’s many sides?

PATRICIA CLARKSON: In order for me to play her, I had to have the façade clearly in place. She has a beautiful veneer, a beautiful house, a beautiful daughter, a beautiful husband, a beautiful life, but behind all of that is just a ferocious beast. And I had to embrace the beauty and the beast. I had to embrace both sides, the dichotomy of this woman and many layers in between. So it was an unexpected journey, even though I knew what was coming.

Was there one side that was easier to grasp?

No. They were equal. The veneer was exhausting, and the monster, the beast is… [pauses] debilitating. [Laughs]

When Adora’s with Amma, is she the beauty or the beast? She coddles Amma when she has fits, but there’s also this scary tension between them.

Adora lost a child and has an adult child that’s long gone, in more ways than one, so she’s clinging to the one thing she has left, and the idea of losing that child is unbearable. This child will never grow up in her eyes. Amma will always have pigtails and ponytails and the dollhouse. This child can be 40, and Adora would still want her to play with toys and to be dependent upon her and need her and love her. It’s a toxic love.

What is it like for you to play in such a dark space?

Well, on set, there were some very dark days, and as grown-ups, we’ve all been through dark days before, but these were some of the darkest. [Laughs] And some of the most unusual… It was fraught at times, but we all knew at the end we had to get to these places because this story lifts into the sky. [Raises her arms] It is not a small tale.

At the end of the day, I adore Eliza and Amy, and how I feel about them off screen aided me on screen. I think all of Adora’s actions are led by an uncontrollable love and need, but at the end of the day, with Amy and Eliza, it’s like, “Okay, that was fun.” And we’ll go home and the next day we start again.

Now, Gillian had told you not to read the book, right? How did that affect your performance?

Yes, she did. She liked that I only knew Adora in this script form. I knew the story, but she said, “Don’t read the book.” I read the first three episodes, that was all that was written, and then they started to tell me the others, and I said, “Oh my goodness.” I remember closing my eyes on the phone with her and with Marti [Noxon, executive producer] as they were talking about Adora. At one point I just went, “Oh, wow.” [Laughs]

What were they saying that struck you?

Just her journey. It’s… Look, be careful what you wish for, but I love being challenged as an actor. I want someone to take to the sky. So often we can coast as actors, we can be lazy, we can be selfish, but this part demands us to be better than ourselves, to think outside.

What has helped you think outside for Adora? Is there a costume, a line, that helps you ground her, or like you say, take her to the sky?

Well, those nails. It’s a weird thing. I have just normal nails, you know [shows her short, manicured nails], but something about having very long nails — it limits your ability to do things, and it changes the shape of your hand in a way. It was transformational. And I was the one that wanted her to have these long nails, these beautiful long nails that just keep people out. But anyway, the clothes I wear and the heels, they definitely helped define this character. She’s such a physical, external character… until the walls start dropping.