Confirmed news is still somewhat ambiguous as to how Batman will fit into Zack Snyder's "Man of Steel" sequel, but the prevalent rumor is that the film features the Dark Knight fighting the Man of Steel. Oddly enough, DC Comics and Warner Bros. attempted this same concept in 2002 to help get a new Batman film off the ground. Geek Tyrant has posted a script for "Batman Vs. Superman" written by "Sleepy Hollow" scribe Andrew Kevin Walker with revisions by "A Beautiful Mind's" Akiva Goldsman that shows what might have been if the project hadn't been scrapped.
"Batman Vs. Superman" features a DC Universe where Clark Kent and Lois Lane are getting a divorce, just as Bruce Wayne is getting married after hanging up the cape and cowl five years prior due to the murder of Dick Grayson. However, when his new bride is killed with Joker toxin on their honeymoon -- years after the Joker's death -- Batman comes out of retirement with a taste for revenge.
It's an intriguing take on what could have been the start of a DC Cinematic Universe at the beginning of the 2000s, but made some changes that fans would have limited its ability to continue into sequels. Dick Grayson and Alfred Pennyworth are dead, as is James Gordon. Barbara Gordon is the current police commissioner and Batman goes far darker than in any other film, nearly murdering the Joker. Although Superman gets some excellent scenes exploring Smallville, there's very little development for him other than an exploration of his romantic relationship with Lana Lang.
There are also minor appearances from Perry White, Jimmy Olsen, Toyman and more.
Regardless, it's certainly worth the read. It's ultimately unlikely that director Zack Snyder and screenwriter David S. Goyer would use any of these concepts or ideas for the "Man of Steel" sequel, but the script reads like a good Elseworlds story with a bit of the dark nature of Tom Taylor's "Injustice: Gods Among Us" prequel comic. Check out the full script below.