At the first test screening for “Promising Young Woman,” writer-director Emerald Fennell wanted to sit in the back so she could gauge the audience’s reaction. When the lights went down, she was stricken with terror. “I thought, ‘No, oh, my gosh, what if everyone hates it?’” she remembers. “This is a nightmare!”

And so it was. During the film’s surprising and brutal climax, two audience members entered into a shouting match, with one of them yelling, “If you don’t like it, you don’t have to stay!” The other walked out. “That’s not what you necessarily want from your first test screening,” Fennell says.

Her leading lady, Carey Mulligan, disagrees. Recalling the film’s electric premiere at the Sundance Film Festival in January, Mulligan says: “No one was sitting comfortably in their seats. You could feel their stomach muscles all tightened up. I think that really is a rare thing. It does provoke a reaction that is unlike anything I’ve seen in a long time.”

That’s the promise of “Promising Young Woman,” a radical, genre-blending thriller that introduces Fennell as both a distinct cinematic voice and a blunt social commentator. Mulligan stars as Cassie, a former medical student whose life has been derailed by the rape of her best friend, Nina. After dropping out of school to care for the broken Nina, who is never seen in the movie, Cassie is adrift and boiling over with rage.

Read the full interview here.