Before he returned to the desolate wasteland that "Mad Max" calls home, George Miller nearly became the director to bring DC Comics' Justice League to the big screen.

His movie, titled "Justice League Mortal," was not simply in development -- it had a full cast in place in 2007, with Warner Bros. planning to have the film hit theaters in 2009 before the entire project was scrapped by the studio.

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Now, the behind the scenes story of the movie is set to be told in a new documentary from director Ryan Unicomb and producers Aaron Cater and Steven Caldwell. Announced via Inside Film, the movie is not yet a sure thing -- the filmmakers have not yet approached Miller or his producing partner Doug Mitchell with their pitch, and they acknowledge that without them on board, the film will likely not happen.

"We wanted to get the story out there to help us to gauge interest," Unicomb told IF, explaining why they've announced their idea before having all the pieces in place, and pointing to the inspirations for the documentary. "I have always been fascinated with project, which would be in the same vein as 2013's Jodorowsky's Dune and this year's The Death of Superman Lives: What Happened?, about a Superman movie that Tim Burton was to direct in the 1990s."