By Sharon Clott Kanter
Updated Oct 31, 2014 @ 5:45 pm
Credit: Jerome Corpuz

Jake Gyllenhaal dropped nearly 30 pounds to play a sleazy newbie photographer in Nightcrawler, in theaters today. Its Halloween release makes perfect sense—this flick is g-r-i-t-t-y. Gyllenhaal stars as crime-hunter photographer Lou, who roams L.A.'s streets in the wee hours of the night hunting for gory scenes to film and then sell to local news producer Nina Romina (Rene Russo).

And he's not afraid to twist what he finds to make his footage a more compelling sell. “[This film] challenges the idea of what success is, and what we’ll do for it," Gyllenhaal said when he and Russo chatted with InStyle at the Toronto International Film Festival. “There are no rules, and the idea is that if you can get away with it, then it’s okay.”

To look the part of someone so starved, Gyllenhaal, who also produced the film, cut calories from the start of the project. “In my opinion, it was a requirement for the character,” he said. “He didn’t have a job or a lot of money, so I had this idea that he was really hungry in a lot of ways—both figuratively and literally." Which is why he compared Lou to a nocturnal predator. “Dan [Gilroy], the director, and I talked about animals that come out at night to hunt for food, and in the script there are a lot of references to coyote," explained Gyllenhaal. "Lou is one of the coyotes searching this new topography trying to make a name for himself.”

Credit: Jerome Corpuz

Co-star Russo was impressed with his transformation. “I don’t know how he focused on his character losing all that weight, nevermind whatever else he had to do as a producer,” she said. “He was dedicated.”

Check out the below trailer for the film, in theaters today!