ELLE – Very few actresses can say that they’re proud of their co-star for successfully transforming into a serial killer, but for Kaya Scodelario that’s the new normal. Playing opposite Zac Efron’s Ted Bundy in the highly anticipated film Extremely Wicked, Shockingly Evil and Vile, Scodelario takes on the role of Carole Ann Boone, wife of the infamous serial killer. “You could tell that he was really passionate about doing this,” Scodelario told me over the phone. “He was on set all the time. He never returned to his trailer. He wasn’t distracted. He wasn’t on his phone. He wasn’t who you imagine Zac Efron to be.”

But that’s not the only role the young actress has on the docket this year. Scodelario is currently in production on Spinning Out, a forthcoming 10-part series on Netflix, and she has also found time to be the star of Cartier’s new Clash de Cartier collection campaign, the latest from the brand. Here, we talk more about her love of jewelry, prepping to play the wife of a serial killer, and why she hopes Spinning Out will change the way the world talks about mental health and elite athletics.

You’re the new face of the Clash de Cartier campaign. Why did you want to work with the brand?

We got talking and I sort of learned that as a brand they’re very passionate about things outside of just their pieces. They have an incredible women’s initiative in business and they hold a huge conference every year. They do a lot of work for the environment. They make sure that everything is bought sustainably and morally. Right off the bat, that felt very much like something that I could respect. Then they talked a lot about my culture, and being half Brazilian, and half British, and how they felt that translated well into what they wanted to do with the Clash selection. The idea of two sides my personality combined is something that I’ve never really gotten to celebrate very publicly before and it’s something I’m very proud of. My mother, who is Brazilian, raised me on her own, so I’ve always felt very much Brazilian as opposed to British. Even though I don’t look it, unfortunately. I just thought that was really wonderful that they saw that within me and that they wanted to use that. They liked my character, my charisma, my strength. They didn’t wanna dull me down.

The campaign is all about clashes. What is a clash about yourself that people wouldn’t know or couldn’t see off the bat?

It’s definitely the culture clash within me. I can be painfully British and polite, I say thank you and sorry a thousand times a day. At the same time, I’m very in touch with my emotions and I’m very vibrant. That definitely comes from my mom. Combined, I think that’s the reason why I’ve been able to do this job: I’m able to have my family roots, but I can also jump on a plane, travel around the world, and attend parties. That’s definitely the biggest clash within me.

Were you a jewelry person before you worked with Cartier?

Definitely. For me jewelry is the thing that puts the stamp of your personality on an outfit. There’s a lot times where I’ve been working a twelve hour day, and I’m getting up at eight a.m. with my son and we need to go to lunch with someone and I’ll throw on a comfortable pair of jeans and a gray tee shirt. Then I’ll think, okay, I need something that takes this to another level and makes me feels feminine and makes me feel fierce. I’ll put on a great necklace or a pair of earrings, and they’ll just make me feel like I’ve lit up.

You wore Cartier for the Pirates of the Caribbean: Dead Men Tell No Tales premiere a while back. What was that experience like for you?

It was amazing. I was incredibly nervous. I had a three month old son and I felt really scared going back out on the red carpet. These gorgeous ruby Cartier earrings came out and I when I put them on, I almost cried. I felt like the little girl in me who dreamed of being a movie star was looking back at me in my reflection. It was the cherry on top of everything. It made me feel ready to go out on the red carpet and own it and be proud of myself.

You play Carol Anne Boone in Extremely Wicked, Shockingly Evil and Vile. How did you prep for the role?

I really loved doing that story and research. It’s the first time I’ve played a character who may still be alive, or that at least existed once. For me, I really wanted to dig into that. We managed to find some archival pictures of her doing interviews, because she was very vocal during the trial. She almost took on the role of his publicist. She would give interviews to the press and defend him quite rigorously, so I had that to work with. I could get her voice down and her mannerism and her jaw line—she had a bit of an underbite—things like that. Then I also felt it was important—because we had so little information on her and out of respect for her—to do my job as an actor and interpret those emotions how I felt they should be. I also did a lot of research on women who write letters to men on death row. There are many different studies on that and one that I found quite interesting said they find that they’re the idea of the perfect boyfriend because they know where they are all the time. Every time they answer the phone they are excited to speak to you, they need you, you help them. There’s a motherly instinct that comes into that as well.

What was it like watching Zac Efron transform into Ted Bundy the serial killer?

I oddly, even though I didn’t know him before that job, felt really proud of him. You could tell that he was really passionate about doing this. He was on set all the time. He never returned to his trailer. He wasn’t distracted. He wasn’t on his phone. He wasn’t who you imagine Zac Efron to be. He was just a very dedicated, focused actor. He took it very seriously. You could tell he’d done his research and he really cared about portraying it as honestly as possible and telling the story. I found that to be really reassuring and I think it’s part of the reason why it was very easy to act alongside him.