In Mission: Impossible—Rogue Nation, opening Friday (July 31), Rebecca Ferguson plays an MI6 agent named Ilsa Faust, who may or may not be on the side of Ethan Hunt (Tom Cruise) and the Impossible Mission Force team.

What is clear about Ilsa is how much ass she kicks. Using her legs to disassemble her massive opponents, she’s as deadly as she is beautiful.

Ferguson did all her own stunts, training for six hours six days a week in preparation for the role. So when she calls the Straight from a car driving around Los Angeles and starts to cough uncontrollably, we’ve caught her in a very rare moment of weakness.

“I’ve done an intense action movie for eight months and I might die choking on salmon,” she croaks, before a publicist temporarily shutters the interview and promises that she’ll call back.

She does, and if she’s fazed about it, it doesn’t show. “Anyways, you asked me what it was like to come into an already established team,” Ferguson says, once the salmon is down, without a beat missed. “And the answer is it was phenomenal. They didn’t have to put energy into it to make me feel at home. But Tom [Cruise], being the guy he is, he just chooses incredible, kind, happy people around him, so I cherished every moment. I watched them work and I learned a lot.”

Ferguson speaks with a British accent adopted from her mother, even though she was born and raised in Sweden, where she now lives. After becoming only the fifth Swedish-born actress to be nominated for a Golden Globe, for her work as Elizabeth II in the BBC miniseries The White Queen, Ferguson sent in a tape to audition for the role of Ilsa.

Apparently, Team Cruise liked what they saw, something that took the 31-year-old actress by surprise. “I was really looking forward to kicking some ass after riding horses and wearing sandals,” she says. “I had actually asked my agent if there was any sort of small, independent movie that I can kick some ass in and learn some moves? And they said, ‘Yeah, there’s a film called Mission: Impossible, what do you think?’ And I said, ‘Yeah, that’s not gonna happen.’ And here we are. It’s intoxicating.”

Even though fame is rippling its way through Ferguson’s life, she’s adamant that it hasn’t affected her daily routine or the way she perceives herself. Perhaps the best reflection of that is the fact that she still lives in a Swedish seaside town, perfectly content to spend her downtime far away from the lights of Hollywood.

“We have three airports,” she replies, when asked if she’s had to consider a transatlantic move. “And I like the combination. It’s a fab lifestyle to be able to travel all around the world and meet different people and see different cultures, and then I come home to kicking off the heels, putting on some big woollies, and going for a walk in the woods.”

No word on whether she finishes that walk with a salmon dinner.