Warner Bros. has embarked on several unreleased, canceled films based on DC Comics superheroes, with many of them attempting to bring several of the heroes together on the big screen. None is more infamous among these than Justice League: Mortal, the film that could have led to a much different DC Cinematic Universe.

Through a myriad of reasons, however, not least of which was the success of The Dark Knight, the movie never saw the light of day. Still, released information about the film enticed interested DC fans, and with more behind-the-scenes photos being released recently, the equally troubled production for the film's documentary has resumed. Here's a look at the movie that could have been, and how the film's failure to materialize inevitably led to the similarly failed 2017 Justice League.

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THE STORY

The script's plot combined elements of well regarded Justice League comic book storyline Tower of Babel, the still recent story Superman: Sacrifice, as well as minor elements of JLA: Liberty and Justice and Crisis on Infinite Earths. In the story, the heroes are all already established, though they are not necessarily acquaintances yet. For instance, the film would have been the first meeting between this version of Superman and the Flash.

The basic premise was that someone had hacked the files in Batman's Brother Eye computer satellite, and thus gained information on the weakness of various superheroes. Likewise, rich entrepreneur, Maxwell Lord, is revealed to be the power behind the throne. The lone survivor of the psychic experiments birthed from the OMAC Project, he now plans to use his abilities to take over the world and slaughter the metahumans that might stand in his way. The script is filled with action, with the various heroes not only facing off against the OMACs but thanks to Maxwell Lord's manipulation, each other.

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CAST AND CREW

DJ Cotrona Justice League-Mortal

The film was set to cast D.J. Cotrona, Armie Hammer, Meagan Gale, Common and Adam Brody as Superman, Batman, Wonder Woman, Green Lantern, and The Flash, respectively. Aquaman and Martian Manhunter had not been officially cast, though Hugh Keays-Byrne was rumored to play the latter. Likewise, Jay Baruchel was set to play the villainous Maxwell Lord. The casting of the World's Finest is in stark contrast to what viewers would have been used to at the time. Superman had last been portrayed by Brandon Routh in Superman Returns, but its critical and financial disappointment led WB to move away from a sequel. Likewise, Christian Bale had played the Caped Crusader in Batman Begins and was set to reprise the role in The Dark Knight, a film whose success was unforeseen even by WB.

The costumes for the cast were both distinct and instantly recognizable. Superman's costume looked like his future Rebirth suit, basically the classic costume sans trunks on the outside and with blue boots. Batman's look was essentially an even more armored, pouch carrying version of the Nolan movie look, giving him the appearance of a slim, all-black version of the Dark Knight Returns suit. Flash, Green Lantern and Martian Manhunter looked straight out of the comics, while Aquaman's look combined his classic look with the '90s hook hand armor. This design was eerily prophetic of how the character would look in the video game Injustice 2. The character with the most altered design was Wonder Woman. Though recognizable, the Amazon Princess's costume was essentially a Victorian version of her Kingdom Come look, contrasting both her classic look and the modern Greco-Roman armor from the Rebirth comics and the DCEU.

Without a wildly successful narrative for their characters to be tethered to, Warner Bros. planned on using Mortal to branch out solo film franchises for each of the heroes. It was for this reason that younger actors were chosen, with the hope that they would narratively grow into the roles in future films. The script was written by Michelle and Kieran Mulroney, the latter of which would go on to write films such as Sherlock Holmes: A Game of Shadows, Power Rangers and Geostorm. The script received positive feedback, which caused WB to fast track the film's production in light of the recently canceled planned Wonder Woman and Flash films. By late 2007, Mad Max creator George Miller was signed on to direct, while Barrie Osbourne was going to produce. Osbourne had been executive producer of a varied list of films, from Child's Play and Dick Tracy to the Lord of the Rings trilogy. With a purported budget of $220 million, the movie was set to begin production in Australia.

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WHY WAS IT SHELVED?

One of the biggest reasons for the film's shelving was the unmitigated success of Christopher Nolan's Dark Knight Trilogy. The first entry, Batman Begins, was already successful and well-received in its own right, unquestionably correcting course after the character's reputation had been destroyed on-screen by Batman and Robin. It was The Dark Knight, however, that truly made the series a pop culture and box office behemoth. Its success, as well as its grounded tone, made using it as the basis for any extended universe problematic, to say the least. That's to say nothing of the fact that Nolan and Christian Bale essentially wanted nothing to do with such an idea, with Bale stating that "it'd be better if [Justice League] doesn't tread on the toes of what we're doing." He also personally felt that a team-up of this magnitude would be best kept until after the then tentative third Nolan Batman movie, which wouldn't release until 2012.

Though Warner Bros. had hoped to get the ball rolling on the film before the 2007-2008 Writers Strike, the production was put on hol in November of 2007. It would resume in February of 2008, with the majority of the filming planned to take place in Sydney, Australia. Sadly, Warner Bros. was unable to secure a tax rebate for the film, as the Australian government felt that despite the production crew being comprised of nothing but Australians, there were still not enough locals involved in the film's making. This pushed production to Canada and also delayed it until July of that year.

By that time, however, The Dark Knight would begin its reign of pop culture domination, forcing Warner Bros. to quickly change lanes in terms of how they planned to create a shared cinematic universe. The failure of 2011's Green Lantern further delayed any moving on the Justice League: Mortal script. 2012 would bring the end of the Nolan Trilogy, while 2013 brought the controversial but financially successful Man of Steel. The latter film jumpstarted the official DCEU, eventually resulting in 2017's Justice League movie. This film was a failure in its own right on many levels and continues to cause debate over behind-the-scenes changes and planned content to this day. As much as the fabled "Snyder Cut" is desired by fans, Justice League: Mortal is its own missed opportunity, one which equally inspires continued interest from the fans.

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