Rose Glass’ genre-bending drama “Saint Maud” stars Morfydd Clark, whose portrayal of a nurse spiraling down into a whirlpool of ecstatic faith after the death of a patient under her care has mesmerized audiences and critics. It’s a star-making vehicle for Clark, who’s in New Zealand, shooting “The Lords of the Rings” series for Amazon. Clark can also be seen in Armando Iannucci’s “The Personal History of David Copperfield,” scene-stealing as David’s first love Dora (she also plays his mother). When she met Iannucci, “It was a meeting-your-heroes moment, and he kind of surpassed all my expectations. He was just so nice and funny and generous and offered me two roles. I really loved the fact of the double casting because David Copperfield was searching for a comfort that was taken away from him too soon.”

“Saint Maud” was a very demanding role, what attracts you to a role like that?

I think fear of being rubbish. When I read something that I actually feel that I can do, where I’m like, “Oh, my gosh, I have to get this,” and I really felt that with Maud, I felt that it was a character that, if I was able to write anything, I want to write a character like that and discuss the big themes that Rose discusses in it.

What was the key to the character?

I spoke to members of my family who work in health service. And sometimes I’ve experienced burnout firsthand. And that there was like, a lot of guilt in not being able to do enough and in feeling they’ve done something wrong, particularly for members of my family who are working in health services now. So that guilt, I was like, well, that makes perfect sense. That kind of religion is so comforting to [Maud] because she can cleanse herself. And when that’s denied to you, that’s just devastating, because it’s like, “Who am I?”

Maud changes her name and her life in the film.

I have ADHD, and I recently realized how much I “masked” as a teenager onwards, because I suddenly was like, “oh, if I act like this, which is me, I will get shouted at”. And I think there’s an element of masking in her. Maybe she’s neurodivergent. I think women do it in general anyway to deal with lots of different situations. And so that kind of helped find why this person had changed their name and become someone totally different.

“David Copperfield’s” Dora is so different. And diverges from the book in that she sees that David is not the one for her.

I love that final scene that Armando wrote — I think she’s masking, like a hyper-femme, pleasing, marriageable woman. And I thought a lot about what she was like, alone, in her bedroom. And like when she was alone, I think she just had zero energy. She uses it all up out in public. But I really love that instead of Dora dying [as she does in the book], she makes a choice: This isn’t for her or for him. I think that scene is what allowed me to be like, “Oh, I can see her so much in such a broader spectrum.”