Olivia Wilde plays the mysterious Ella in "Cowboys & Aliens"Continuing the tradition of strong, mysterious female roles, Olivia Wilde plays Ella in the new Universal/Dreamworks release based on the Platinum Studios comic, "Cowboys & Aliens." The actress, known for her role as Thirteen on TV's medical drama "House" and the isomorphic entity Quorra in last year's "Tron Legacy," told CBR News and other journalists that mystery adds to good roles. "I think every great character has a great secret; I think that's the trick to creating a great character in a film. I always try to pick one secret that the person is holding," Wilde explained. Answering questions about the film, Wilde also discussed her fascination with Joan of Arc, women as a box office force, and the possibility of creating a new type of female role.

"I think it makes it more interesting and layered that what you're saying is not always what you're thinking," Wilde continued. "Sometimes a secret is bigger than others. Both for 'Tron' and 'Cowboys,' she's holding a big secret."

Wilde considered herself lucky to win the part as there were "many highly qualified actresses who wanted this role." The actress remembered that the part came to her in a strange way, but, she said, "I ended up feeling I was born to play this role, and it's certainly my favorite role I've ever played."

According to Wilde, the script landed on her doorstep in the middle of the night. "I read it in an hour and a half. It had a letter in it that described who was involved, and I thought, 'Wow, we've got the perfect storm of genius involved.' We've got Spielberg, Ron Howard, Brian Grazer, Jon Favreau, Bob Orci, Alex Kurtzman, all these people who I really respected," she recalled. "I read it and I found it so unpredictable and so interesting. The movie takes this turn at a certain point, and my character in particular takes a big turn."

When she met with director Jon Favreau, she learned the real reason he was considering her for the part. "He had seen me in a movie that was not very successful that his children really liked called 'Year One' with Jack Black," admitted Wilde. "They had been playing it incessantly in their hotel room in Hawaii. He kept seeing it and in the background he would notice there was a strange princess of Sodom -- that was me."

Though Craig's Jim Lonergan is tight-lipped, Ella has secrets of her own

"You never know with films, what will lead to what," she added. "I feel that it was all meant to be and it brought me here."

As with "Tron Legacy," the actress used Joan of Arc as an anchor point for Ella. "The idea of a martyr, of a warrior being willing to sacrifice themselves for the greater cause definitely held over from 'Tron' into 'Cowboys and Aliens,'" she said. It also informed her research into women of the period. "Whether they were prospectors, ranch hands, cowgirls, madams... it was very tough to be anyone in the Old West, but particularly women." The actress also took into consideration the unusual place Ella holds within the film's western trappings. "She was a gun-slinging woman who was very mysterious, because she's wearing this prairie dress -- she has no corset, she doesn't fit the look already. She's wearing this gun -- why is she wearing a gun? Why is she alone? She can ride with the men just as good or better, and she's holding this big secret."

She expressed hope that the character will launch a new sort of archetype for the genre. "Certainly when I was growing up and watching Westerns I identified with the men -- I wanted to be Steve McQueen. I didn't have any women I identified with," she said. "I hoped -- and I still hope -- that Ella can be that for young women. We kept that in mind while we were shooting. That's also something I thought about during 'Tron.'"

After a pause, she added, "Maybe that's just my process: Joan of Arc, badass woman."

Wilde welcomes the opportunity for more starring roles in sci-fi films for actresses

One thing she is sure of is the impact "Tron Legacy" had, most notably in the fashion world with Quorra's angled bangs and the overall sleek look of the film. "It was wild to see how the 'Tron' aesthetic did take off, though," Wilde went on. "We started seeing it in a lot of different places, on runways and certainly some hairstyles. Kanye -- that was wild. I was like, 'Woah!' The Black Eyed Peas. 'Tron' has always had that effect on people -- look at Daft Punk. It resonates with pop culture." She hopes "Cowboys & Aliens" will also add to the churn of fashion and style. "I think that the Western look comes back into fashion every once in a while; it is right now, and it's perfect timing for us. A little fringe never hurts. I think that it's a good look, and it's something uniquely American."

Of course, in the film, Ella has but one costume: the prairie dress. Asked if the lack of costume changes made things dull, she recalled working on "Tron Legacy" and that film's infamous skin-tight suit. "I would rather wear a little cotton prairie dress than that suit any day," she laughed. Wilde also wore little-to-no make-up in the film, which she felt was a refreshing change. "I look like me more in this movie than I do in any other," she said. "It also sets Ella apart from the classic Western female character and I had a lot of fun with that, being very bare."

Between "Tron Legacy" and "Cowboys & Aliens," Wilde is emerging as the next big sci-fi actress, a position she says she is quite comfortable with. "I think there's some great sci-fi films in the works that have some really interesting female roles," she explained. "It takes people really taking risks and understanding that the public will go see a movie starring a woman." While the prevailing opinion has been that female-driven films do not sell tickets, the actress pointed out the recent comedy hit "Bridesmaids;" a film written by a woman with a primarily female cast. She also noted science fiction's tradition of strong female leads that began with Sigourney Weaver's turn as Ellen Ripley in "Alien." Wilde added, "We're moving forward, and hopefully I'll get to do more sci-fi roles and take on more of the burden on my shoulders in terms of playing the lead as opposed to the wise, helpful female sidekick."

Asked if there was one particular sci-fi role she would like, the actress quickly knew the answer. "I grew up as a Trekkie, which is really funny. I think [in] 'Star Trek,' they were always great female roles, but there's no reason the captain shouldn't be a woman," Wilde said. "I think we could do Captain Kirk as a woman."

"Cowboys & Aliens" opens in theaters Friday.