By Jake Coyle, Film Writer

TORONTO (AP) --

Dan Gilroy, writer-director of the Los Angeles noir "Nightcrawler," knew his star, Jake Gyllenhaal, had entered an adventurous new phase as an actor. But he still didn't foresee the sudden emergence of a hair tie.

"One day he goes, 'Can I put my hair up in a bun?'" recalls Gilroy. "And you're looking at him like, 'Oh my god, he's putting his hair up in a bun."

In "Nightcrawler," which opens in theaters Friday, Gyllenhaal plays Lou Bloom, one of the more fascinating cinematic creatures of recent years. He's an LA drifter who's anything but aimless. He spends his days on the Internet, soaking up the motivational lingo of corporate America, and his nights scavenging in the Valley. Coyotes were an inspiration. With wide-eyed wonder and cutthroat ambition, Lou discovers the sordid business of freelance videography for local TV news, filming murders, fires and fatal car crashes.

The bun (which Gilroy, supportive of his actor, acknowledges was briefly "a political football") is only one detail that further inflates Lou's unique creepiness, but it's a telling one. It's an example of Gyllenhaal's eagerness for experimentation and newfound confidence as an actor.

"There's a big part of me that just stopped taking things so seriously," says Gyllenhaal. "Part of me was like, (sniffing) 'That smells good. Let's go.'"

"Nightcrawler," a darkly comic, enthrallingly disturbing portrait of our universal appetite for lurid tragedy, marks a high point in Gyllenhaal's maturation. A few years ago, crossing 30 and coming off a few regrettable films like the big-budget "Prince of Persia," the "Donnie Darko" star resolved to return to trusting his instincts.

"It wasn't too difficult for me to say: I need to start listening to that instinct again. I need to start reading and looking around for what inspires me," he says. "That doesn't mean just work. That means life in general. There were a lot of changes that happened as a result. I left Los Angeles and moved to New York. I spent a lot of time with my family, more time than I ever had. I made a lot of changes in my life."

In an interview shortly after "Nightcrawler" premiered at the Toronto Film Festival, Gyllenhaal exudes earnestness and ease. Part of it is simply "feeling like my own man," he says. Gyllenhaal, 33, now views many of the directors he works with — "Prisoners" director Denis Villenueva, Antoine Fuqua (who recently directed the boxing drama "Southpaw" with the actor) and Baltasar Kormakur (the upcoming mountain climbing thriller "Everest") — not paternalistically, but like "cinematic brothers."

"It was like freedom," he says of the shift. "There was more play."

In Gilroy, a longtime screenwriter ("The Bourne Legacy") and first-time director, Gyllenhaal says he found "a creative soul mate" he was willing to do anything for. Gyllenhaal lost considerable weight for the role, and in one scene, he was so carried away that he punched a mirror, injuring his hand.

"He's made a conscious decision to go for unconventional material that challenges him and challenges the audience," says Gilroy, brother of "Michael Clayton" director Tony Gilroy and husband to Renee Russo, who co-stars in "Nightcrawler" as local news producer. "He's one of the most fearless actors alive. I don't think he's afraid of failure. I think he's afraid of mediocrity."

This period for Gyllenhaal started with David Ayer's LA police thriller "End of Watch" and was followed by a turn as an obsessive detective in the kidnapping drama "Prisoners." Gyllenhaal experimented with a tic for the character, who blinks erratically. "I tried it and it just felt right," he says.

"I've never worked with anyone that was walking a tightrope like Jake had to walk," says Russo of Gyllenhaal's "Nightcrawler" performance. "He wasn't eating and he was always hungry. He had to be so focused. That is such a difficult role and he made it look so easy. You don't want to look psychotic, completely."

On the contrary, Gyllenhaal — who clearly relished the character — says, giggling, "I love Lou. The things he says!" The actor happily spouts chunks of Lou's dialogue at length, like, "Who am I? I'm a hard worker. I set high goals and I've been told that I'm persistent."

The scene comes from not an office job interview, but a scrap metal yard Lou's just tried to steal from. Gilroy calls Lou an extreme expression of today's job market "and what choices young people are forced to make to make their mark in the world and to sustain themselves."

In Gyllenhaal's eyes, Lou is a warped superhero, tailored to today's times.

"The things that he gets away with are extraordinary,' Gyllenhaal says. "He's a success story. This is the ultimate success story for today."

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