David Harbour Steps Away From Tony Gilroy’s ‘Behemoth!’ After ‘Stranger Things’ Wrap

David Harbour has officially exited Tony Gilroy ’s highly anticipated film, Behemoth!, after wrapping up his work on the last season of Netflix ’s sci-fi phenomenon. The actor, best known for his role in Stranger Things , decided to step back from the project, citing the need for rest following the intense production schedule of the show’s two-hour series finale, which aired on New Year’s Day 2026.

Gilroy, the creative force behind Andor , is both writing and directing Behemoth! for Searchlight Pictures. The story centers on Alex Serian, a musician from a family of musicians, who returns to Los Angeles. The film is described as a heartfelt tribute to movie music and the people who bring it to life. The ensemble cast features Pedro Pascal, Olivia Wilde, Eva Victor, Matthew Lillard, Alexa Swinton, Margarite Levieva, and Barry Livingston.

Behind the Scenes: Casting and Preparation

During an appearance on Lovett or Leave It, Gilroy shed light on Pascal’s preparation for his role, explaining why the actor was seen leaving the gym with a cello in hand. According to Gilroy, "He's a cellist in the film. He's practicing the cello very diligently and plus, we want him to be able to carry the cello anywhere he can because... when we did The Devil's Advocate, when Keanu [Reeves] first came in I remember we were like, 'He's gonna be a lawyer? Oh my God...', and I remember Taylor Hackford said three months out: 'You gotta put a suit on now and you're never f****** taking that suit off until we start shooting', because he looked so weird in a suit. Three months later, he'd worn a suit everywhere he ever went and he had, like, it worked. And carrying a cello case will turn you into a cellist if you do it long enough."

With Harbour’s departure, the production will need to recast his role, but the rest of the cast remains intact, promising a dynamic lineup for the film’s release.

Harbour Reflects on the End of an Era

Harbour’s decision to leave Behemoth! comes as no surprise to those who heard him speak at Rose City Comic Con last fall. The actor opened up about the emotional toll of saying goodbye to Stranger Things after a decade with the Duffer Brothers and the rest of the cast and crew. He shared,

I mean, it's so surreal... for me, reactions are always delayed. I almost couldn't process it. I can't tell you what our last day on set was, because it's a huge spoiler, but it was a very big culmination... and I couldn't believe that that was our last day. I was like, 'Oh my God. They really did time it so that the biggest thing that happens in the series for him, in a certain way, is this moment.' And so I was really focused on playing the crap out of that moment too. And then it just happens, and it's just over.

He continued,

I've known those guys, the Duffer Brothers, for 10 years, and we've been through so much together, and that cast and that crew, it's just like, it's really hard to process. It took me, like, another six months to really know how I felt to be honest. It really just passed through so quickly. It felt very, very surreal.

What’s Next for ‘Behemoth!’

With Harbour stepping away, Behemoth! will move forward with a new actor in his place. The film’s unique premise and star-studded cast continue to generate buzz, especially with Pascal’s dedication to his role as a cellist. As production continues, fans are eager to see how Gilroy’s vision comes together on the big screen.