The controversial Los Angeles-based art collector, dealer, and “cultural entrepreneur” Stefan Simchowitz will take a short break from frightening gallerists to frighten moviegoers in Darren Aronofsky’s upcoming horror flick Mother!, which premieres at the 74th Venice Film Festival on September 5.

According to Simchowitz, Aronofsky invited him to join the cast on set for a day of filming, and flew him in to try his hand at acting. The pair are close friends and previously collaborated on Aronofsky’s critically acclaimed drama Requiem for a Dream, which Simchowitz produced.

As for what Mother! is about, all that has been revealed is that it’s about a happy couple, played by Jennifer Lawrence and Javier Bardem, whose home is visited by another sinister-sounding couple played by Ed Harris and Michelle Pfeiffer—and that something unspeakably horrifying happens. The official longline for the film reads: “A couple’s relationship is tested when uninvited guests arrive at their home, disrupting their tranquil existence.”

Aronofsky, meanwhile, told Vulture that audiences should enter the theater “[k]nowing that there’s some terrifying secret at the core of this thing, that the film’s going to go there, and you should only come if you’re ready to get on that roller coaster.”

In an email to artnet News, Simchowitz said that “doing a scene with Jennifer and having Ed Harris, Javier, and Michelle Pfeiffer on set with you on your very first acting day ever on three hours’ sleep was pretty amusing.” He seemed surprised to learn that he had made it into the movie. “If I am even in the film it will be a small role,” he explained. “I have not seen the film, so I have no idea where on the cutting-room floor I fell.”

Simchowitz is credited with a role in the film on IMDb, indicating that he did indeed make the final cut.

As for details about his character, the dealer declined to divulge anything further. “I don’t want to talk about the film before its release,” he said. “Nevertheless, go see the movie— it’s going to be one of Darren’s best. It’s a real beast of a film.”

Fingers crossed that the spine-chilling secret has to do with the LA art market!