Kristen Stewart gets fierce to bring Jack Kerouac's 'On the Road' to the big screen

In "On the Road," Kristen Stewart turns into a wild child. Yes, there's nudity and drugs and much irresponsible behavior, but more importantly, Stewart, playing Mary Lou, who's based on the real-life LuAnne Henderson, has to bring a primal fierceness to her character.

"The most difficult part about flipping into the part was to just be able to do her justice in the way she moved people — to be that infectious, undeniable presence in the room," Stewart says on the phone from New York.

Stewart, 22, says she herself is more of an observer than a firebrand.

"I want to find people like that. I want to watch them. I'm definitely not the one people are chasing after — I do a bit more of the chasing," the former "Twilight" star says.

You wouldn't be able to tell that from the smoking dance scene in which Mary Lou dazzles everyone with her natural heat. It was the scene Stewart knew she had to nail — even though she's not a dancer and it involved no dialogue.

"I was very intimidated by that scene because it's the one opportunity that I had to show that she did represent IT, that IT people talk about when they reference 'On the Road,'" Stewart says. "It was important for that scene to completely illustrate exuberance."

"On the Road" was Jack Kerouac's thinly disguised memoir of his rowdy times in the '50s criss-crossing the country with a group of misfits and poets, and testing society's boundaries.

The Kerouac character is Sal (Sam Riley), who is caught in the spell of Dean Moriarity (Garrett Hedlund), based on the legendary party animal Neal Cassady. Mary Lou is Moriarity's runaway child bride, up for seemingly anything.

The book became the Bible of the Beat Generation and has inspired countless fans — including Stewart — over the years.

She thought it was important to get a good picture of the real LuAnne before tackling the part. Taped interviews with LuAnne gave her some perspective.

"She passed away right before we were going to get this thing together, but I sat down with her daughter for a couple of days, and these tapes that were hours and hours long kind of served to put a face on her," Stewart says.

"In the book, she jumps off the page; she's the kind of person who you're at a party with and you can't help looking at her," Stewart says. "But you're not on her ride with her, so you're not exactly sure where her head is, where her heart is, and these tapes offered that."

When it comes to acting, Stewart knows where her heart is.

"I can't imagine turning my back on something that fuels me this way," she says.

That will come as a relief to Hollywood. Stewart first gained notice playing Jodie Foster's diabetic daughter in 2002's "Panic Room." She quickly became an in-demand actress, working with Sean Penn on 2007's "Into the Wild" and starring alongside Meg Ryan that same year in "In the Land of Women."

But everything changed when she took on the role of Bella in the "Twilight" series, which has earned more than $3.5 billion worldwide since 2008. In 2012 alone, Stewart's films "Snow White and the Huntsman" and the "Twilight" finale "Breaking Dawn - Part 2" earned more than $1.2 billion worldwide.

It's enough to make a person want to keep their day job. But it's not about the money.

"I worked really hard in high school to keep options open and go to school if I wanted. And when that time came, I already felt so challenged," she says. "I feel the same way now. I can't imagine stepping out of this.

"It's definitely an odd inclination to have," Stewart says. "I just sort of want to tell stories. If I could just stay following that feeling, I'm very happy doing that."

'On the Road'

Opens Friday

Rated R for strong sexual content, drug use and language

Running time: 124 minutes

Kristen Stewart

Born Kristen Jaymes Stewart on April 9, 1990, in Los Angeles

Discovered at age 8 by a talent scout while acting in a Christmas play

Co-starred with future "Hunger Games" star Josh Hutcherson in 2005's "Zathura: A Space Adventure"

Lifetime domestic box office total at age 22: $1.7 billion

Average domestic earnings of a movie she's in: $84 million

Her reported salary for "On the Road": $200,000

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