Spike Lee’s BlacKkKlansman made its Croisette debut last night to a rapturous welcome, complete with that most over-hyped of Cannes staples: the endless standing ovation. No surprise. Lee’s first movie in Cannes’ main competition since Jungle Fever in 1991 is a searing call-to-arms to a post-Charlottesville world, and the filmmaker’s most impressive work in years.

Earlier in the day, before the movie screened, Lee visited Deadline’s Cannes Studio with his stars John David Washington and Laura Harrier to talk us through his attraction to the story. Washington plays Ron Stallworth, a Colorado Springs undercover officer who successfully infiltrated the Ku Klux Klan, ultimately becoming the leader of its local chapter and gaining the trust of Grand Wizard David Duke (Topher Grace).

The project came to Lee after being developed by Blumhouse and Get Out director Jordan Peele. Peele immediately identified Lee as the man to bring it to the screen. Said Lee: “When he explained it to me, my next words were, ‘Is it true?’ People say, ‘Didn’t Dave Chappelle have a skit like that?’ I could see why Jordan and his team thought this was something that would work [for me].”

He thought of Washington, the son of Malcolm X star Denzel, almost immediately. “The Washington/Lee families have been tight for years,” Lee laughed. “Brother man to the right, if you go on IMDb, hopefully, you’re going to read that Malcolm X is number one. He’s one of the kids that says, ‘My name is Malcolm X.’ How old were you?”

“Six,” said Washington. “Oh my god. And six takes. He kept saying, ‘Listen to Uncle Spike…’ I was a little excited. I nailed it though; I felt like we got it.”

Harrier plays a fictional character in the film called Patrice Dubois, but she’s inspired by the heroic women of the Black Power Movement. “Angela Davis and Kathleen Cleaver, who Spike introduced me to,” Harrier said. “[I was] drawing from these really powerful women who were such a huge part of this movement. I don’t think we’ve heard their stories enough.”

Lee said it was important for the film to recognize those heroines. “We knew about Angela Davis and Kathleen Cleaver, but they weren’t the only sisters who were right by H. Rap Brown, Eldridge Cleaver and Bobby Seale; they were very much part of the movement.” He joked: “We would have been crucified [not to include Patrice]. Black Twitter would have torn our ass. You ain’t been torn up ’til Black Twitter tears your ass up. And right now, they’re killing Kanye.”

Lee first glimpsed Harrier in her breakthrough role in Spider-Man: Homecoming. “I said, ‘Damn, they got a Spider-Man with a sister,'” Lee laughed. “I was hip about it.”

Casting Topher Grace as Duke, Lee said, was an idea suggested by their shared agent. It’s an inspired bit of casting, and Grace is perfectly-pitched and frighteningly dark in the role. “I got to give Toni Howard credit, because it never crossed my mind,” Lee admitted. “And she never does that. If you looked at his body of work you might not think of him as David Duke. But what he did? Jesus Lord.”

For more from Lee, Washington and Harrier, check out the video above.