Morfydd Clark never expected to become an actress. Born in Sweden and brought up in Wales, Clark has always struggled with dyslexia and severe A.D.H.D. Since the age of seven, she “was medicated, and school was not easy,” she explains. “I’m now looking back and realizing that when school started to become O.K., it was basically because I was just performing ‘good student.’ And I think that made acting seem natural to me.”

At 16, Clark left school altogether. “My mom didn’t want me sitting around doing nothing. But she never expected me to go to drama school,” something Clark had set her mind to. “My ambitions were very small then. I did National Youth Theatre of Wales and National Youth Opera. I was finally in an environment where the bits of me that were very much issues in school were suddenly celebrated,” she says. “That was a real turning point.”

From there, Clark landed a series of supporting roles in major productions, including as the young counterpart to Sally Hawkins’s traumatized character Jane in the offbeat British comedy Eternal Beauty, and an irascible nurse in the HBO adaptation of the popular Philip Pullman fantasy books, His Dark Materials. Most recently Clark was cast in two separate parts in Armando Iannucci’s The Personal History of David Copperfield.

Clark, now 30, cemented her breakout status with this year’s Saint Maud. The debut feature from British writer and director Rose Glass, it has been described as “mesmeric,” “electrifying,” “nerve-shredding,” and “the year’s best horror film.” In it, Clark plays Maud, a devoutly Christian hospice nurse and caretaker to an American cancer patient played by Jennifer Ehle. The relationship slips from nurturing to enthralled to obsessive—after reading the script for the first time, Clark says, “I just wanted to meet the brain that had come up with this.”

This past month, Clark was named British actress of the year at the London Critics’ Circle Film Awards and was nominated for a BAFTA Rising Star award, as well as being long-listed in the leading-actress category, owing to her performance in Saint Maud.

“It just seems kind of unreal. When I became an actor, I just hoped I’d work,” she says as we wrap up our video call, from the remote North Island of New Zealand, where she’s filming Amazon’s much-hushed new Lord of the Rings TV series with its reported billion-dollar budget. “In the last few years, my world has surpassed my wildest dreams.”

Saint Maud is available to stream on Epix

Bridget Arsenault is the London Editor for AIR MAIL