For fans of Bret Easton Ellis, American Psycho is a genius work of black social comedy, with its film adaptation a bona fide cult classic. One fan of the book and film in particular was Roberto Aguirre-Sacasa, writer of the book for American Psycho – the Musical, directed by Rupert Goold with music by Duncan Sheik, which opened April 22 at the Gerard Schoenfeld Theatre. It closes today after a total of 81 performances, and the show has proven that even if a show doesn’t find the kind of commercial success its team hoped for, it can still be a triumph for all involved. American Psycho succeeds due to its insistence on being a complicated shot in the arm to Broadway and the enthusiastic response from Ellis’ devoted fan base ensures it will live long after the the Broadway cast takes its final bow.

Aguirre-Sacasa first read Ellis’ work in college and again in graduate school, and saw the film on its opening weekend. “I thought it was a chilling, sharp and brilliant metaphor—investment banker by day, serial killer by night,” he says.

The film version is beloved by fans of the original text due to faithfulness to its sources, and the stage adaptation has created something of a cult of its own for repeat viewers. (A group of girls at a recent performance returned for their fourth viewing.)

For Aguirre-Sacasa, this fascination with the piece might be because of how Ellis’ text bent the rules of its genre, something that he in turn applied to the musical adaptation. This genre-breaking led the team to classify the show as the “anti-musical.” “For me, and for Duncan Sheik (composer/lyricist), there was a big watershed moment when we realized that this isn’t going to be a big musical comedy like Legally Blonde.” This decision, to write something that was fundamentally dark with the comedy coming second, resulted in a piece that remains true to its morbid roots while also expressing deep satirical smarts.

Aguirre-Sacasa also noticed a “kind of kinship” between American Psycho and Kander and Ebb’s Cabaret. “There’s a real darkness to both that show and to American Psycho that musicals rarely engage with. There’s a sense of humor to both shows, but they’re both extremely bleak.”

Aguirre-Sacasa exacerbates this bleakness in his stage adaptation, which melts into a violent, stylized fever dream in which Patrick Bateman begins to lose his grip on reality. Aguirre-Sacasa knew that he had to delicately balance both the nihilism and comedy of the book with the satirical and horrific aspects of the film. “The book is laugh-out-loud funny, and the film is as well, but it’s also a horror movie.”

He also knew to lay heavy emphasis on the “iconic” scenes that fans remember and look forward to seeing onstage. “There are some scenes you just have to use,” he says, before referencing the scene from the film which Patrick Bateman moonwalks to “Hip to Be Square” by Huey Lewis and the News before dressing up in a plastic raincoat and bludgeoning a co-worker to death with an axe. This insistence on honoring iconic details results in massive cheers and applause from the audience—especially when “Hip to be Square” blasts through the sound system. The production team leans in to the satire and fan reaction, selling plastic raincoats at the merchandise counter.

American Psycho hits these obvious references, but Aguirre-Sacasa also filled his story with Easter Eggs for the most die-hard fans, such as the book-only scene in which Patrick has an excruciatingly awkward elevator run-in with Tom Cruise, who lives in his building.

The musical also appeals to its original fan base by its direct engagement with our collective nostalgia. The 1980s as a decade is a character just as much as Patrick Bateman, with references to the musical Les Misérables (which debuted in 1987).

Much of the humor plays on the cyclical nature of time where so much that was old is new again. Ellis’ novel makes heavy use of Donald Trump, and the decision to throw in a few references to Trump into the musical was, to Aguirre-Sacasa, about showcasing the kind of person Bateman was, not about making a political argument about today’s Trump. Aguirre-Sacasa also used a reference to Milli Vanilli because “I wanted to be in dialogue with the pop culture of the ’80s and how awful it was.”

Aguirre-Sacasa argues that what makes American Psycho so beloved by its hardcore fans is it doesn’t offer any easy answers. Instead, it presents a world of chaos. “Big Broadway musicals often reaffirm the world order, and that’s great! But this show doesn’t. It’s ambiguous.” This bold engagement is one of the many reasons why fans flock to the show.

For fans of the book and movie, American Psycho – The Musical seems to follow in its predecessors’ footsteps to cult classic status. Despite the short life of the musical on Broadway, Aguirre-Sacasa is confident that the show will continue to find life in the hearts of book and film enthusiasts. “I knew people liked the book, but this is like Rocky Horror!” he says. “I just went and saw the show again, and when the title of the musical goes up, people cheer. When Patrick comes out in the raincoat, people cheer. There’re so many cultists. And,” he laughs. “I guess, in a way, I’m one of them!”