EW: It’s nice in LA. It has a heartbeat from the earth, where you hear it singing through the levels of volcanic rock and palm trees and glaring sun like, “Boom-boom, boom-boom, boom-boom.”

MS: You hear the train here. “Choo-choo, choo-choo, choo-choo.” But my friends made me apply [to college] because I am a weird math dork, and I got nice scores on tests. So I did, but I never had any intention of going to school. I moved to New York the summer after high school. This was a little more three years ago now. Lo and behold, here I am a year into school and think it’s the greatest thing in the entire world.

EW: And they let you defer two years?

MS: The second year I wrote a letter that was like, “I have all these neat projects lined up.” And I had White Girl!

EW: Are you going to be a mathematician?

MS: No. People ask me that a lot.

EW: What kind of job do you do with a math degree?

MS: Act!

EW: Why do you go to school for math if you don’t want to do something with math?

MS: Math is the thing that makes my brain shake the best, in the good way. When I meet with an advisor or other math majors, they tell me not to major in it unless I’m going to become a professor, because it’s a deep hole. Maybe your brain shakes too much if you go down that hole.

EW: But you must have some secret fantasy.

MS: When I was in high school and started to get into math, I had a secret fantasy of being a physicist. But I enjoy being creative more. I don’t think I could handle a non-creative job.

EW: The most creative and exciting class I ever took was theoretical physics. Very simple equations, but it was mostly the ideas.

“This felt like a script about young people that
I usually don’t read because most
of the scripts are these goofy, kind of sweet,
high school comedies. White Girl
was something about this age that felt real.”
— Morgan Saylor

MS: I see the ideas in mathematics in acting a lot.

EW: I was trying to explain to people the graphs you did for White Girl. Can you explain that?

MS: With White Girl specifically, I was beginning to figure out how actors could have a method to the madness. You could prep and figure out a way into the storytelling. So one of the big things I did for White Girl was timeline it out. The script is 80-90 pages, and maybe has 100 or 110 scenes. “Act One” is only a few days, then “Act Two” is only two days, but a lot of things happen—there are like 50 scenes in it. We talked a lot about Leah’s different highs, and not just in terms of drugs, not even manic, but her highest highs and lowest lows. “Is she more intense in this scene as opposed to this scene?”

EW: Because when you’re shooting out of order, how do you chart where you were in one scene versus another? Before we shot, I swore to you that we’d shoot it on film and in order—two things that went out the window very quickly. We both did a lot of preparation on telling a story where, more than most films, you have to respond to what just happened for it to make sense. “This happened, therefore she feels sad, feels happy, feels up, down.” If those those performances or feelings weren’t connected, the film would just fall apart.

MS: Because Leah is such the driving force….

EW: She alone is in every scene of the movie. Literally almost every frame of that movie, except for one time we see a curtain. And the one time we see India getting fucked. Besides that, you are in every second of the film.

MS: I think of that mathematically in a bigger sense too—there’s the arc of the entire story and perhaps the derivative of that is the character’s arc. I believe there’s a lot to that, but I sound like a crazy freak. On top of that, I trust my gut more than anything. I drop the math when I’m on set. Because you can’t think about a fucking graph when you’re trying to act.

EW: We both had to connect to the character, all the characters and the through-line, which is really hard to do! We did a lot of work because we had the luxury of time, the drive and the fear of God in us to make sure it made sense, while some people would take it for granted that editing would figure it out.

My goal for your role was finding someone who didn’t confuse me with what kind of human they were. You were just such a real person that I wanted to work with you. I can’t help but being super critical of people who want to act in general—but not you. Even though I’ve tried to act and thought it would be fun, I wonder, “What is that impluse?” Do you feel like you’re unusual as an actress?