“If you think of race as the third rail of this country, I think it’s something that’s incumbent on us and imperative for us to try to do something about it,” Director Kathryn Bigelow said of Annapurna film Detroit.

Speaking on a panel at Deadline’s Contenders event in Los Angeles on Saturday, Bigelow was discussing her new movie, which tells the true story of the 1967 seige of the Algiers Motel during the Detroit riots. After a starting pistol was fired inside, Michigan State Police and the Michigan Army National Guard raided the hotel, eventually resulting in the deaths of three black men, who were later found innocent of any wrongdoing.

For Will Poulter, embodying the ringleader of the racist officers was tough. “The challenge I faced was to try and build a psychology based on the racist and highly-flawed rhetoric,” he said. “There was a shared goal to try and do justice to the facts of what happened, and I think we all had to go to uncomfortable places,” he added. “But we were all united in the greater goal of this film, which was as, as Kathryn said, to try and effect some real social change.”

As moderator of the panel, Deadline’s Mike Fleming Jr. asked if playing a person with such prejudiced views had made Poulter self-conscious on set. In response, co-star Algee Smith raised some laughs when he said, “Will was apologizing so much you would have thought we were in a relationship.”

Smith plays a member of R&B group the Dramatics who heads to the Algiers Motel to escape the riots and finds his life irrevocably altered. “I had this idea of this guy in my head who starts on one track,” he said, “and then in one night, his whole thought process completely changes to a fight for survival instead of a dream that you have to make your life better.”

Questlove, who wrote It Ain’t Fair for the soundtrack, said he hadn’t known all of the horrifying details of what happened  until Bigelow screened the film for him. “It became personal to me,” he said. Explaining that he’d wanted to stay away from the “feel-good gospelized song,” that some might expect, he said, “I can’t recall many films that made me cry this way, or made me paralyzed.” The musician told Bigelow of the song he planned to write: “‘It won’t be Oscar-worthy, but just for my soul I want to create something that’s probably going to be eight minutes long.’ Most black people, we can’t even take a knee peacefully, I wanted to do something that’s like, ‘Damn they’re really kind of angry in the last three minutes of this song.'”