Making superhero movies is a tough gig, and behind the scenes, there is a lot of pressure to bring something to life that will make hundreds of millions of dollars. The MCU and DC are the biggies at the box office, and even those franchise films aren’t always able to run perfectly.

During the 90s, superhero movies still had a ways to go, and a major tonal shift was made when Joel Schumacher and Val Kilmer took over for Tim Burton and Michael Keaton on the Batman side of blockbusters. There was a lot of conflict between the two, and at one point, they nearly brawled it out.

Let’s look back at what happened between Joel Schumacher and Val Kilmer.

Schumacher Was Warned About Val When Kilmer Became Batman

Every now and again, stories will emerge about a performer painting them in a negative light. Sometimes, it could just be a singular issue that spiraled out of control, but other times, this is a pattern of behavior that indicates the type of person someone is when the cameras aren’t rolling. Prior to working with Val Kilmer on Batman Forever, director Joel Schumacher was warned about the movie star’s behavior.

According to Entertainment Weekly, James Jacks, the original director of Tombestone, shed some light on the type of guy that Kilmer was on set. Jacks would say, “There’s a dark side to Val that I don’t feel comfortable talking about.”

Per Jacks, Kilmer himself would even say, “As you know, I have a reputation for being difficult. But only with stupid people.”

Unfortunately for Schumacher, he didn’t quite get what he was in for when he began making Batman Forever with Kilmer in the cape and cowl. In an interview, Schumacher would reveal, “I had heard horror stories about Val and was warned not to hire him. But I have heard that about many talented people, hired them anyway, and had no problems whatsoever.”

Clearly, there were two sides to Kilmer behind the scenes, and one has to imagine that Schumacher was hoping to work with the nicer version of the movie star. Instead, Schumacher had to deal with someone who wound up pushing him to the edge and nearly instigating a physical conflict.

Related: How Much Was Michael Keaton Paid For ‘Batman’?

Kilmer’s Behavior Sparked Tension On Set

Kilmer and Schumacher had the potential of being a dynamic duo together when they embarked on the journey to make Batman Forever, but after some time on set, things would break down between the two.

Schumacher, per Insider, would say that he and Kilmer “had a physical pushing match. He was being irrational and ballistic with the first AD, the cameraman, the costume people. He was badly behaved, he was rude and inappropriate. I was forced to tell him that this would not be tolerated for one more second. Then we had two weeks where he did not speak to me, but it was bliss.”

This was a whole different level of bad from Kilmer, who clearly reverted back to being the version of himself that James Jacks had talked about. This could not have been comfortable for the other people that were on set and forced to witness it, but eventually, things would simmer down and the film wound up being made.

Related: Why Is The Infamous ‘Batman And Robin’ Considered The ‘Most Important Comic Book Movie Ever Made’?

Barbs Were Traded Publicly

Batman Forever did go on to be a success at the box office, and it brought in a new era for the character. Instead of coming back and reprising the character in the film’s sequel, Val Kilmer was replaced by George Clooney.

Years after spending a tumultuous time together on set, Joel Schumacher would open up about how he still felt about Kilmer and about Tommy Lee Jones’ treatment of Jim Carrey. Jones was the man who played Two-Face in Batman Forever. Schumacher would say, “He was fabulous on The Client. But he was not kind to Jim Carrey when we were making Batman Forever. And I didn’t say Val [Kilmer] was difficult to work with on Batman Forever. I said he was psychotic.

That’s right, years after the fact, Schumacher still thought that Kilmer was psychotic. The duo would never work together again, and in his memoir, Kilmer would share some kind words about Schumacher, saying, “Our director, Joel Schumacher, brought kindness to spare. He was charming to strangers and family members (and especially gracious with my mother) and for the most part sensitive onset. But everyone has their tough days and there’s always super pressure with superhero films as they burn about 100,000 calories a day.”

Related: This ‘Game Of Thrones’ Star Is A Huge Batman Fan

Though they came close to blows, Kilmer and Schumacher wound up making a successful film together.

Next: Zack Synder Makes An Official Announcement of ‘Justice League’ Release Date