Charlize Theron Runs for Her Life in Netflix’s ‘Apex’ First Look (Exclusive)

Charlize Theron is running for her life in PEOPLE’s exclusive first look at Apex.

Netflix’s action-packed Apex is a cat-and-mouse thriller in which Taron Egerton, 36, plays a serial killer hunting Theron, 50, through the wild in Australia.

“A grieving woman testing her limits in the Australian wilderness is suddenly ensnared in a deadly game with a ruthless predator,” reads a synopsis.

While Theron is an action-movie veteran, the Oscar winner tells PEOPLE that preparing for Apex and its stunts involved more work with extreme sports than learning new fight choreography.

“In this case, I was climbing a lot. I was climbing pretty much every day,” she says. “And when I got to Australia I was kayaking a lot. That’s a massive workout. I was just getting a strong as I could because I climb all of the actual mountains in the movie. I’m climbing all of it — and I’m climbing it barefoot on my own raw feet.” 

Despite Theron’s expert-level climbing in the movie, she says she only got into climbing for the first time for this role. “I had never climbed, except for trees when I was a kid in Africa,” she says. “It’s great. It’s so much fun.”

Theron and Egerton teamed up with Icelandic director Baltasar Kormákur for Apex.

“It was fascinating seeing Charlize transform and take on the different challenges that the role required. From an avid (barefooted) climber to a great kayaker and swim through crazy rivers, not to mention fight for her life,” he tells PEOPLE via email. “We decided not to take any shortcuts and just dig in and go through it, and she certainly did.”

Egerton sports a shaved head as he hunts down Theron’s character in the movie. “I was very excited by not having to worry about what my hair looked like every day,” the actor says. 

Theron says filming Apex in the wild in Australia required the small cast and crew to hike to their filming locations at times. The movie also offered her a long-awaited opportunity to work with Eric Bana, whom she says plays her onscreen partner.

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“I have been trying to work with Eric for over 20 years,” she says of Bana, 57. “We have literally circled each other on projects and it’s just never worked out, so this was kind of a no-brainer. I stepped in right away and I was like, ‘Eric’s playing this part,’ and he was kind enough to come and join us for three weeks. He’s amazing in the film.”

Apex is on Netflix April 24.