You might have noticed a mysterious figure scaling a movie billboard in New York City today. No, it wasn’t Spider-Man. That was Apex star Charlize Theron, showing off the intense training that prepped her for her new action film now streaming on Netflix. 

In honor of Apex’s April 24 Netflix release, Theron scaled one of the film’s billboards at Times Square’s Pentacular on the corner of 7th Avenue and 49th Street. 

In Apex, Theron plays Sasha, an expert rock climber who finds herself stranded in the Australian Outback with a depraved serial killer (Taron Egerton) on her trail. There’s no way of training for that, but Theron was able to immerse herself in the world of climbing with the help of celebrated American rock climber Beth Rodden. 

Rodden is no stranger to treacherous climbs: her ascent of Yosemite’s infamously difficult Meltdown surface came a full decade before another climber was able to repeat her performance. “Hearing her story and her expertise, I thought, this is the most badass, best climber you could be with,” Theron told Netflix. “She’s the OG.”

Upon beginning work with Theron, Rodden had no idea what to expect. The Oscar winner has a long resume of action spectaculars, from Mad Max: Fury Road to The Old Guard films, but climbing was another matter entirely. 

“I didn’t know if I was going to like it. I’d never climbed before, except as a kid in Africa climbing trees, which I loved,” Theron said. “And I weirdly climbed barefoot, so I was kind of prepping for this movie without knowing it.”

Fortunately, Theron had other work to fall back on, including her training as a ballet dancer, which she undertook at Chicago’s renowned Joffrey Ballet before a knee injury changed her career path.

“The first thing that struck me was she had such good body awareness,” Rodden told Netflix. “I think that comes from her dance background and just how hard she works at her craft.” 

Theron and Rodden started training on climbing walls in Los Angeles, approaching the challenge like any other art form. “You don’t learn how to climb,” Theron said. “You really are lucky if you have a person like Beth, who can open up this door to how organically beautiful the art of climbing is. You can’t put it in a box, and there is no recipe.”

Rodden had trained other rock climbers before, but this was her first stab at working with an acclaimed actor with no prior climbing experience. “It’s just so different to take somebody brand new, totally willing, totally excited, really wanting to learn,” she said. “We went around to a couple different gyms, and by the second or third one, I was like, ‘Oh, you’re nailing it.’ ”

Of course, in Apex, Sasha is no beginner climber. To get ready for the horrific journey her character goes through, Theron had to train for increasingly intense scenarios.

“It was interesting because I’ve had a lot of martial-arts and fighting training, and most of the action work I’ve done lives in that world, but this was very different,” she said. “This is about endurance and strength. The technique of climbing is really beautiful because it doesn’t conform to one thing; it’s a real art. You have to make it your own and put in the hours to understand it.”

Soon enough, Theron was climbing in jeans and even bringing her children along for outings with Rodden. “We have kids who are about the same age,” Theron said. “We would go climbing with them sometimes, and that was when it got really special.”

By the end of the training regimen, climbing became therapeutic for Theron — just like it was for her onscreen character. “Beth would put me on walls sometimes that I just could not get by, and instead of being like a drill sergeant, [there was] just this calmness about her,” Theron said. “There were days that I would go, and I was going through stuff, and it just felt like a way to forget about things.” 

The most important lesson Rodden taught her movie-star protege might sound counterintuitive. “I just remember on the first day I would ask her, ‘So what should I do?’ ” Theron said. “I kept asking that a couple of times, and then it finally sank in to me. Her response was always, ‘I don’t know.’”

In other words, there’s no right way to climb, only a lot of very dangerous wrong ways. “Climbing is cathartic,” Rodden added. “Everybody has an individual way to do it.”

Rodden, by the way, says Apex is one of the few movies that gets rock climbing right.

“I was blown away by how Charlize climbed in the film and how the film portrays climbing. Usually, Hollywood films are totally sensationalized and mess up a lot of things that climbers would never do,” Rodden said. “But with Apex, everybody from the producers to the director to Charlize, they all wanted to make it as realistic as possible — what climbers would actually do, how they would move, what equipment they would use.”

Apex is now streaming on Netflix. Get your climbing gear ready.