The hard part about making a movie from Louis Zamperini’s life story is that his life was barely plausible enough to be a movie in the first place. Zamperini was born in 1917, the delinquent child of Italian immigrants, and grew up to become a track star: he made the U.S. Olympic team when he was only 19. When World War II broke out, he became a bombardier in the Pacific theater. In 1943, his plane went down in the ocean.
Zamperini drifted in an open boat for 47 days, subsisting on rainwater and raw fish before washing up on the Marshall Islands. He spent the next two years in brutal Japanese prisoner-of-war camps, where he was singled out for persecution by a sadistic Japanese officer. He barely survived, but through it all he never lost hope, and his life is a monument to the human ability to endure and persevere.
Hollywood has been toying with Zamperini’s story for more than 50 years–Tony Curtis was going to play him in 1956 but made Spartacus instead. Now on Dec. 25, Unbroken arrives in theaters, starring a little-known English actor named Jack O’Connell as Zamperini. Its director is better-known, though not for being a director: she’s Angelina Jolie.
Jolie’s life is in some ways only a little more plausible than Zamperini’s. She’s gone from a B-movie actress to an Oscar winner to one of Hollywood’s priciest stars. (She topped Forbes’ list in 2009, 2011 and 2013.) In the ’90s her turbulent personal life made her a staple of the tabloids; now she’s a devoted wife (to Brad Pitt) and mother (to six kids, three biological, three adopted). She’s also a leading humanitarian–two years ago she was made a special envoy for the U.N. High Commissioner for Refugees–and last year she revealed in the New York Times that she’d had a preventive double mastectomy. Now she’s a director; Unbroken is her second film.
Based on all that, you would expect Jolie to be a dervish of manic energy, but in person she’s calm and still. She doesn’t fidget. She looks very much as she does on camera, with large eyes and full lips and Maleficent cheekbones. Zamperini’s story is one of suffering, but Jolie was drawn to its uplifting core. “Traveling with the U.N., there’s so much that can feel so overwhelming and so negative,” she says. “And then to have an example like Louis, who was this little Italian immigrant troublemaker who didn’t think he was worth anything–I needed it. I needed something positive to get me through all the things that keep me up at night.”
For somebody who’s spent so much of her life in front of cameras, Jolie seems pretty relieved to get into the director’s chair. “I don’t want to be that person in the spotlight,” she says. “I’m much more at home sitting with the sound guys and the grips, in my boots, working.” In fact she has a kind of nerdy affinity for the nuts and bolts of filmmaking–she lights up when she talks about those aspects. Laura Hillenbrand, who wrote the hugely best-selling biography on which the film is based, recalls Jolie asking her to figure out what color uniform a high school track-and-field team would have worn in 1935. “My heart soared at the question,” Hillenbrand says. “It’s easy to fudge things. It’s hard to be devoted to doing things right. She’s taken the hard path.”
Jolie’s background also gives her a special feel for her actors: she sees her set as a protective bubble, free of distraction, where emotion can safely come out. “In terms of the configurations, scheduling, admin, all that boring stuff, she really kept that separate,” says O’Connell. “I only recall on set one conversation that wasn’t relevant to what we were doing there, and that was my fault. I started asking her about the Beatles, if she’d met them. And it turns out she had.”
On occasion, Jolie had to balance her protective instinct with her obsession over detail. For the scenes at the 1936 Olympics, she made the cast wear old-fashioned running shoes. “The shoes exercise a different muscle, and their legs were cramping,” she says. “The mother in me would say, ‘Let’s go home–let’s call it.’ I had to be the director and say, ‘Five more times!'”
Zamperini died this past July, at 97, but Jolie spent enough time with him to form a deep bond: his children, Luke Zamperini and Cynthia Garris, describe Jolie and Pitt as honorary Zamperinis. She showed a cut of the film to the man himself in the hospital on her laptop. “If it was only for this moment, I was happy I made the film,” Jolie says. “It was one of the most profound moments of my life. I brought it thinking he would have some critique on filmmaking. It was just a man watching his life and remembering his friends. It was beautiful.”
She has already gotten her most important review, but Jolie shows no signs of resting on her laurels. Since Unbroken wrapped, she married Pitt–after seven years together–and she has already shot another film, By the Sea, which she wrote and co-starred in with her new husband. “We just finished it about a week ago, this little independent movie about grief and marriage and life,” she says. “Brad and I did it together–on our honeymoon, we played a very unhappily married couple.”
Unbroken is a biopic, but there is a small undercurrent of autobiography in it. Like Zamperini, Jolie had a wayward youth, and like him she found her career, purpose and place in life. “I think I do connect to people who could be written off as wild or dark, or who are just full of fire and looking for a place to put that fire,” she says. “It’s an important lesson to learn, and it’s something I did learn: you live on behalf of others and you’re happier and you have purpose. And you have a great excuse to have all that fire.”
This appears in the December 01, 2014 issue of TIME.