The Joker has premiered to rave reviews from almost everyone who's seen it at festivals, pointing to what could be one of the best comic book films made yet. Still, even with the final product getting critical acclaim, the process of actually making it sounds sort of awful.

Speaking to the New York Times, co-writer and director Todd Phillips explained the method behind the madness star Joaquin Phoenix created for his role as the Clown Prince of Crime and it sounds like a lot for his fellow co-stars to put up with. "In the middle of the scene, he'll just walk away and walk out," Phillips revealed. "And the poor other actor thinks it's them and it was never them--it was always him, and he just wasn't feeling it."

Once the actor cooled off, Phillips said he'd return to set and offer, "We'll take a walk and we'll come back and we'll do it." While that may not sound like the greatest working environment, Phillips and Phoenix clearly thought it was important to his process.

However, there was one actor Phoenix didn't walk out on. Robert DeNiro appears in the film as a late night talk show host that Phoenix's Arthur Fleck is fixated on, and he never found himself on the opposite end of his co-star leaving the set. "Joaquin was very intense in what he was doing, as it should be, as he should be," DeNiro said of his experience with the actor. "There's nothing to talk about, personally, on the side, 'Let's have coffee.' Let's just do the stuff."

And do the stuff they did. Thus far, Joker is enjoying quite a bit of buzz. GameSpot's Michael Rougeau praised the film in his review, writing, "Joker succeeds, without equivocation, because it transforms the villain into the populist antihero we need him to be now. Joker wears its influences on its maroon sleeves, but it also carves its own gashes through the blood-soaked landscape of contemporary comic book movies, offering something that, despite teetering on the shoulders of 80 years of history, is wonderfully fresh, dangerously exciting, undeniably entertaining, and rock-solid in its artistry."

Joker arrives in theaters on October 4, 2019. Don't get too excited about Phoenix's character getting further integrated into the DC film universe, though. Phillips has already confirmed this take on Joker won't meet up with the next Batman, Robert Pattinson