Be aware there are spoilers for The Perfection below.

Odds are, by now you’ve probably heard about Netflix’s wild thriller The Perfection. If you haven’t, get out of here and come back after you’ve watched it! The latest Netflix original comes from The Matador and regular Girls director Richard Shepard, starring Allison Williams and Logan Browning as two cello prodigies wrapped up in a twisted relationship that evolves through rivalry, romance, revenge, and a whole lot more throughout of the genre-bending film.

It’s a twisty and twisted thriller that continually surprises and certainly isn’t afraid to shock, so naturally, I was excited to have the opportunity to speak with director and co-writer Richard Shepard about his inspirations, the film’s most surprising moments and that insane final shot.

Final spoiler warning!

The Perfection stars Allison Williams as Charlotte, a cellist and one-time pupil of an elite music academy who gave up her dreams for ten years to care for her ailing mother. The film begins with a shot of Charlotte’s mother, lying dead in her sick bed, and we a rebirth of sorts as Charlotte sets out on her “mission.” She reconnects with her old music teacher Anton (Steven Weber) and meets Lizzie, the stunning and wildly talented cello prodigy who succeeded her at the academy.

In short order, Charlotte and Lizzie move from rivalry to flirting, winding up in bed and then bonding enough to take an ill-advised last-minute trip together. We know Charlotte is up to something, presumably some jealous act of vengeance, but Williams never gives her character away, and you can’t help but wonder what her game is, even as she feeds Lizzie mysterious pills. There’s a flourish of contagion-like bug horror, and a nightmare scenario about being stuck on a bus in the middle of nowhere during a medical crisis, and as soon as the girls are stranded on the side of the road with no help in sight, Shepard rewinds (literally) the film to give us our first twist — there’s no contagion, no viral infection, and no bugs.

Charlotte drugged Lizzie with her mother’s old pills and uses the power of suggestion to trigger a full-on hallucinogenic freakout, convincing Lizzie that her body is overrun with bugs and the only way to stop it is to chop her hand off. A horrifying act of vengeance against the girl who replaced her — or is it?

Inspired by South Korean revenge horror, and the works of Park Chan-wook in particular (The Perfection often feels like a sister film to Park’s unpredictable erotic thriller The Handmaiden), Shepard devised a film that would never be what the audience expected. “I love the way that [Park] plays with structure and does twists in his movies that are outrageous,” Shepard said, “and yet all somehow make sense in the final film, and I love how elegantly he does all of that.”

Another key influence for Shepard and his co-writers Eric C. Charmelo and Nicole Snyder was the Netflix docuseries The Keepers, which investigated a potential church coverup surrounding abuses of power and the murder of a nun. “That was a major starting-off point for us about the idea of this systematic abuse,” Shepard explained. and that became sort of, ‘Oh, well that will be very interesting, in terms of an underlying plot.'”

That underlying plot bolsters the film’s next few reveals, which are all structured around the fact that Anton is a child rapist and his prestigious music university is built on perverse godly conviction. Based on a horrific “tradition” that Anton himself was once a subject of, the Bachoff Academy of Music has taught systemic sexual abuse for decades. It is a false house of godliness, indoctrinating students to a false faith, wherein the instructors molest young musicians when they fail to achieve “The Perfection,” ie,f to perform without any errors, inside a special acoustic room known as “The Chapel”.

The Perfection is a revenge film, but Charlotte’s vengeance was never against Lizzie, but Anton, his fellow instructors and the institution that taught and enabled them. To the contrary, Charlotte’s mission was to save Lizzie by whatever means necessary, and she knew that her indoctrinated lover would never leave of her own free will. But Charlotte’s drive to save Lizzie didn’t begin with their affair; it stems much deeper. Twice in the film we see the moment where Charlotte and Lizzie pass each other on the stairs as children; Charlotte’s last day at the Bachoff Academy before leaving to take care of her mother, and Lizzie’s first.

“I felt like this was ultimately a story of friendship,” Shepard said. “Allison’s character sees a flashback memory of her as a little girl leaving that academy while young Logan’s character is coming up the stairs, and we see that image twice in the movie. To me, that was what the movie was, which was that Allison could have said something to her, “Don’t go in there,” but instead didn’t, for many reasons. She was a child, she was a victim of abuse; There was a lot of reasons why she didn’t do that.”

All the same, for Shepard, the film hinges on the way that guilt ate at her over her decade away from Anton and the academy, and The Perfection is the story of her revenge, yes, but more importantly, of her quest to save Lizzie from what she let her walk into. “I felt like she had to deal with that guilt for ten years,” Shepard said. “She had to live with the pain of what she didn’t do. So this was a movie about someone trying to correct that. She may be completely misguided, maybe, in the way she did do it, but the fact is that that is what the story is about. So there is a level of redemption and, above all, of empowerment, by her ability to do that.”

Which leads us to the film’s final image. The last and most empowered twist of them all; Charlotte didn’t come back to Bachoff Academy on her mission of vengeance alone; she teamed up with Lizzie to finally bring Anton down. In fact, it was Lizzie’s idea to go there. After a chilling performance in The Chapel that drives Anton’s evil home, Lizzie sets her free and the two take down their tutors, including a brutally bloody fight with Anton that mangles Charlotte’s left arm. Fortunately, Lizzie still has a brilliant right arm and the film’s final shot finds the two women, intertwined on stage, playing the cello together, discovering a new way to make art born out of their shared survivor’s bond. With a thoroughly disfigured (we’re talking all limbs chopped off and eyes/mouth sewed shut) Anton forced to listen in the audience, no less.

Shepard says they found that final image in the writers’ room, but they didn’t know if it could work until rehearsals. He didn’t want to use body doubles or CGI, so he asked both actresses to learn to play the cello, which they pulled off after months of rehearsals. That’s when they got to see that closing shot in play, the two women wrapped around each other playing together and knew that the closing image would work. “It was sexy, and disturbing, and empowering, and crazy, and yet also perfect, in a way,” Shepard said. “It really was [perfect] for what they went through, that they would be tied together like that for the rest of their lives.”

As endings go, it’s also rather romantic — well, at least if you’re as weird as this movie is. “You have been and always will be the person who makes my heart skip a beat when you play,” Lizzie tells Charlotte, her idol, the first time they play together. The Perfection leaves us with the image of them playing together in their victory forever.