When Margot Robbie read the script for I, Tonya, a biopic of the notorious ice skater Tonya Harding, she assumed the story was complete fiction. “I thought the writer was so quirky and crazy to come up with this stuff,” she told me, still looking a bit astonished by the strange twists in Harding’s life. (In 1994, the skater was famously implicated in a plot to take down her nemesis Nancy Kerrigan after a man attacked Kerrigan with a baton.) We were on location for the W shoot in Snug Harbor, a bucolic Staten Island enclave founded in the early 1800s as a haven for old sailors. There was something appealingly run-down and shabby about the setting, but Robbie, who is 27, is a glow-y girl: With blond hair and an engaged manner, she can’t help but shine.

Which is why it is so remarkable that Robbie was able to completely disappear into Harding’s decidedly darker persona. A self-described redneck from Oregon, Harding was the antithesis of the traditional superstar figure skater. She was rough and flashy, and her skating was powerful and athletic rather than graceful and balletic. Harding’s ex-husband, Jeff Gillooly, and her bodyguard, Shawn Eckardt, were ultimately charged with criminal conspiracy to commit assault. While Kerrigan recovered from her injuries in time to compete in the ’94 Olympics, the incident propelled Harding to tabloid infamy and effectively ended her skating career.

“I was 4 years old and living in Australia at the time,” Robbie said. “The news did reach Australia, but I didn’t know about it.”

Riveted by the script, Robbie immediately agreed to star in and produce the film—despite that fact that she had never figure skated in her life. “I did four months of training, five days a week, four hours a day,” she recalled. “On Christmas Eve, I was at the rink. And now I actually really miss it. I kept my ice skates—but I said goodbye to a whole world of pain that I didn’t realize came along with figure skating.”

Not only did Robbie have to be believable on the ice, she also had to take on the even more difficult challenge of assuming Harding’s accent and physique. “Once I put on the wig, which altered my hairline, and bleached my eyebrows, I started to see Tonya,” Robbie said. “The hardest part was losing my natural laugh. It needed to be Tonya’s laugh. I couldn’t do a triple axel like Tonya, but I was able to master her laugh.”

Harding’s life, by her own account, was violent: In the film, her mother (played brilliantly by Allison Janney) physically abuses her, as does Gillooly (played by Sebastian Stan). “I worried that after some of the fight scenes we would never win the audience back,” Robbie told me. “When we screened the film at the Toronto International Film Festival, the whole audience gasped when Gillooly hit her. But six minutes later, he did something kind, and the audience went, ‘Ahhh!’ ”

Robbie paused. “That was interesting to me, and explains something about the insidious nature of domestic violence: The audience forgave him so quickly. So how could you blame Tonya for going back to him?”

Before filming began, Robbie and her director, Craig Gillespie, flew to Portland, Oregon, to meet Harding in person. “I wanted there to be a clear distinction between the ‘real’ Tonya and the one I would be playing,” Robbie explained, adding that she had already made up her mind as to how she would approach the character. “I didn’t want to sugarcoat her,” she said. I asked Robbie whether or not she believes Harding was innocent. “In the beginning, I wasn’t really sure. There were things that didn’t add up. Facts were muddled.” She smiled. “But the more I became Tonya, the more I saw things from her point of view. I’m on her side 100 percent. I don’t think she did anything but be different from what the world wanted. There are cool misfits, and then there is Tonya. She didn’t fit in. And I love that.”

Lynn Hirschberg: Tonya Harding went on to become a boxer. Did you have to learn that sport too?

Margot Robbie: No. I’d already done heaps of boxing training to play Harley Quinn in Suicide Squad. So the boxing wasn’t an issue. I had done a lot of stunts in that film, and I thought, I can pick up things fairly quickly with the right training—I should have this ice-skating thing down in no time. I didn’t realize how extremely difficult it is. There’s no padding when you hit the ice. Our choreographer was never sympathetic. When I fell, she was like, “Come on, get up. Let’s go!” One time I had a huge fall, and she said, “That was a real skater fall, and you can have a minute.” I was so proud, with tears streaming down my face.

Did you enjoy wearing Tonya’s trashy skating costumes?

We replicated every single one. A lot of people have nostalgia for that Tonya Harding period. She sewed her own costumes! And during filming, I sewed the bow on my costume. We had all the actual footage—you couldn’t invent this stuff. In an interview, Tonya’s mom, LaVona, wore a fur coat with an actual bird sitting on her shoulder. If we proposed that idea, people would say, “That’s ridiculous.” But that’s what they actually wore.

Did you go out on Halloween last year? Did you see all of the Harley Quinns?

Yes! A lot of my friends dressed up as Harley Quinn for Halloween. When they started texting me, “What did the tattoo on your right thigh say?” I really thought they were taking the piss. I was like, “Ha ha.” But they wrote back, “No, seriously, we are dressing as Harley for Halloween!” And so many guys dressed up as her, too, which is my favorite thing. Every Halloween I dress as a guy character because they are always the most fun. From Day One, I never got the Halloween slutty costumes. I went out as Jason from Friday the 13th, with my jumpsuit and machete. I was in New York that year, and it was snowing. I thought, Surely, everybody is going to cover up. But every other woman was in lingerie. My favorite costume, though, was James Franco’s character in Spring Breakers. I did my hair in cornrows, put on a Hawaiian shirt and a gold grill on my teeth. I nailed it! I’ve always dressed up as guy characters, so to think that guys are now trying to take on Harley because she’s the coolest and the craziest—that’s pretty awesome.

You have another film, Goodbye Christopher Robin, about A.A. Milne, the creator of Winnie the Pooh. You are much more like a villain in that film than you are in I, Tonya.

My character in Christopher Robin is not meant to be the bad guy, but she does have some less than redeemable qualities. I play Christopher’s mom, Daphne Milne, a very glamorous, aristocratic English woman in the 1930s. If she were living today, she’d be working in fashion. A CEO of a fashion house or something. She’s a hustler. But then she was the wife of an author. So she kept her husband on track, and they built this little Winnie the Pooh empire. Inadvertently, she ends up ruining her son’s childhood.

Daphne and Tonya could not be more dissimilar!

I understand them both, but I miss Tonya more. Some characters, like Daphne, I can let go of very quickly. But not Tonya. I’m still not done with her. I found it hard to shake her off.

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