Charlize Theron took home last year's Best Actress Oscar for her portrayal of a real-life convicted killer in 2003's "Monster." More recently, she has been tearing up the screen as a pioneering female taconite miner fighting sexual harassment in the fact-based drama "North Country." Although the 30-year-old actress may still be, as she says, "young and learning," shouldn't she by now be getting used to taking on such strong leading roles?

Okay, maybe not ones based on thigh-booted, scantily clad rebel assassin-acrobats from the future.

What drew Theron to the title role in "Aeon Flux" -- a live-action feature film (opening Friday) based on the futuristic sci-fi cartoon series by animator Peter Chung that debuted on MTV's "Liquid Television" in 1991 -- was the fact that, despite the character's inner and outer strength, the movie felt to her "like a foreign genre."

But, the actress adds, "I like being out of my comfort zone."

Alluding to the fact that the series was known for its sparing use of dialogue, Theron, who has a 12-year background in ballet, says the thing that fascinated her most about the stunt-heavy movie was the idea of "telling stories with your body." That, and the belief that the adaptation, by writers Phil Hay and Matt Manfredi ("Crazy/Beautiful"), remained true to Chung's dark original vision. Set in a totalitarian regime, where an underground movement strikes back at government oppression with specially trained killers like Theron's character, the film adaptation, by "Girlfight" director Karyn Kusama, makes larger points about the struggle of the individual today, Theron says.

Despite the movie's setting 400 years in the future, "2415 feels very realistic," she says of the theme of social unrest. "I just loved how outrageous this future was and yet how real and contemporary."

A bit too real, at one point. Ten days into filming, Theron seriously injured her neck doing a back handspring, forcing a temporary halt in production. After intensive physical therapy -- not to mention consultation with insurers and producers about how to keep their star safe from that point on -- Theron returned to work. "It's important for me not to compromise," she says.

Compromise isn't often an option for the actress, who says that, whether she's doing comedy (as in a recent recurring role as a daffy Brit on the TV sitcom "Arrested Development") or an action thriller (as in "The Brazilian Job," a reprise of her role as a sexy safecracker for the upcoming sequel to "The Italian Job"), she's always looking for projects that can teach her something she didn't know before. "I'm not very good at doing things just for the sake of being cool. I don't feel I can ever just lean on my crutches."

Um, bad choice of words, maybe, considering her recent luck in the physical storytelling department. Theron is quick to clarify: "Look, making films is time-consuming," she explains. "When you sign on the dotted line, you've made a commitment, so it better be something that is challenging to you."

Yeah, but unlike Aileen Wuornos in "Monster" or Josey Aimes in "North Country," Aeon Flux isn't much more than a two-dimensional cartoon character who runs around killing people without breaking a sweat or mussing up her hair, right? Way cool, to be sure, but as Theron points out, her character's allure -- part sex fantasy, part intimidation, an always winning combination among teenage boys and their middle-aged counterparts -- is only one aspect of her mystique.

"She's still human," she says. "That's the surprise about her. She was created to be this assassin who can switch off her feelings, but at the end of the day she's human, and she soon starts looking for bigger answers. She's someone who's incredibly good at killing and who does her job. She lives with that, and owns that, but there's also this vulnerability to her."

Theron compares Aeon's tough exterior and inner softness to her own. Too often, she believes, there's a public perception of the actress as "thick-skinned," due in part to the fact that she's often portrayed in the media as a quote-unquote survivor: someone who not only comes from the "harsh landscape" and "different culture" of South Africa (where she was born) but whose mother killed Theron's abusive father in self-defense when the actress was a teenager.

"I'm still very much a fish out of water," she says, explaining that although that sense of being an outsider may fuel her art, her career also has its roots in an abiding curiosity about other people.

"Isn't that the reason you become an actress, after all," she says, "because you have this fascination with the human condition? There's a real mystery about every part you play, and something that you learn, and something that you discover. You always gain a little bit more knowledge than you had before. Sometimes, what you walk away with is as simple as learning what other human beings are capable of in certain circumstances."

Charlize Theron uses body language as Flux, a mysterious assassin in the futuristic "Aeon Flux.""I like being out of my comfort zone," Charlize Theron says.