Mad Max: Fury Road director George Miller almost directed a Justice League movie, long before Zack Snyder got his hands on the property. However, as those who knew about Miller's ill-fated superhero film, that movie just didn't happen.

In an interview with The Hollywood Reporter, Miller offered some details on that movie, as well as why it never got made.

The movie in question had a tentative title of Justice League: Mortal. The plot would follow Superman, Wonder Woman, Batman, The Flash and other superheroes as they came together to take on Maxwell Lord (now a main character on CBS' Supergirl) and Brother Eye.

It sounds like a pretty good plot, but because of things going on at the time, the movie never got off the ground. Miller explained why.

"I really was attracted to it. But there was a writers' strike looming," said Miller. "We had to cast it very quickly, which we did with Warner's casting people. And we cast it really quickly and we mounted it very quickly. And it depended on a start date and it depended on some basic rebate legislation that had just got through a new Australian government. But it was just too big a decision for them to make in the time. And that fell through and the whole film fell through. We almost got there. And it wasn't to be. But that happens a lot, where films line up and the stars look like they're aligning and they didn't."

Miller also pointed out that something similar happened with Mad Max: Fury Road on at least three occasions. Eventually, though, that film did get made and ended up being one of the biggest movies of 2015.

However, at least part of Justice League: Mortal will make it to film, as a documentary about the making of it (or rather, the planned making of it). The documentary, though, still requires Warner Bros. approval, so fans probably shouldn't hold their breath.

Miller also realizes that failures like Justice League: Mortal often happen in the film business and gives his perspective on that.

"Initially, when you prepare just one film, you put everything into it. It can be soul-crushing, because there's a compulsion to tell some sort of story," he said. "But as time goes on, you get a little wiser, and you find yourself working on a number of things. And you know that this is a part of the process, it's part of the ecology. That certain things align and it's work."