If Unbroken is a tough story to film, imagine what it was like to live. The movie, which is being directed by Angelina Jolie as we speak, is adapted from the Laura Hillenbrand best-seller of the same name and follows the incredible true story of Louis Zamperini (Jack O'Connell). Zamperini ran in the 1936 Olympics, then joined the armed forces at the outset of World War II. After surviving the crash of his B-24, he spent 47 days adrift on a raft in the Pacific. Eventually he was found unfortunately, it was by the enemy. As if he hadn't already suffered enough, Zamperini was imprisoned in a brutal Japanese POW camp for more than two years. ''On set, we started to joke and say, 'Tomorrow will be easier,' knowing full well that on this challenging shoot, there are no easy days,'' Jolie says via email. ''Anytime it gets tough, we think of the real men who lived through this, and no one complains. In fact, we all just feel honored to be here.''
The film, out in December 2014, marks Jolie's second directorial feature, after 2011's In the Land of Blood and Honey. Production began in Australia's Moreton Bay in mid-October, starting with some of the film's most physically demanding scenes: three men marooned on a raft in choppy waters. O'Connell, Domhnall Gleeson, and Finn Wittrock (who portray fellow airmen and raftmates Russell Allen Phillips and Francis McNamara) arrived on set starvation-skinny after an extreme diet protocol. ''We've begun with the character's lowest points, though, so I'm looking forward to when [Zamperini's] in top form,'' says O'Connell, who's best known for his role on the British TV series Skins. ''Perhaps the makeup will be less extensive so I might get a lie-in, compared to the current 3:30 a.m. calls.'' Kidding aside, the actor feels proud to be playing Zamperini, whom he's met with twice. ''Both times I came away feeling awe-struck,'' he says. As for working with Jolie, O'Connell likes to refer to her as the World's Best Boss. ''She presents herself as an equal,'' he says.
Author Hillenbrand is also pretty wowed by Jolie, whom she speaks to for hours at a time. ''She's extremely bright and subtle-minded and absolutely devoted to getting it right,'' she says. ''She wants every detail to be true.'' Hillenbrand recalls trying to find, at Jolie's behest, the uniform color of a 1935 high school track-and-field team. ''But my heart soared when I heard that question,'' she says. ''It's easy to fudge things. It's hard to be devoted to doing things right. She's taking the hard path.''
Some of Jolie's own hard struggles last May she wrote about her decision to have a double mastectomy after discovering she carried the BRCA1 gene for breast cancer might give her insight into a story about survival. ''She's a very, very resilient person,'' says Hillenbrand. ''And that's really what this story is about. Angelina has demonstrated that in her personal life, and will continue to do so. And Louis is the greatest example of that that I can think of.'' Hillenbrand says Zamperini, now 96, is excited about the film and its director. ''He always says, 'I volunteer to be in the movie as long as I can play Angelina's boyfriend.'''