Batman: Unchained: What the cancelled Dark Knight film should have been like (7 photos + 1 video)
Interesting facts about the unreleased Batman film that Joel Schumacher was supposed to direct. 
"Batman Unchained" was a planned sequel to "Batman & Robin," which Joel Schumacher was supposed to direct. This article provides information about how the filmmakers planned to make it. 
Synopsis
A year after defeating Mister Freeze, Batman, Batgirl, and Robin encounter the mentally unstable scientist Jonathan Crane, also known as the Scarecrow, and Harley Quinn, a toymaker and the Joker's daughter. She seeks revenge on Batman for her father's death. 
Cast
George Clooney as Bruce Wayne/Batman
Chris O'Donnell as Dick Grayson/Robin
Alicia Silverstone as Batgirl/Barbara Wilson
Nicolas Cage as Dr. Jonathan Crane/Scarecrow
Courtney Love as Harley Quinn
Michael Gough as Alfred Pennyworth
Pat Hingle as Commissioner Gordon
Jack Nicholson, Danny DeVito, Michelle Pfeiffer, Tommy Lee Jones, and Jim Carrey as the Joker, Penguin, Catwoman, Two-Face, and the Riddler, respectively.
Preparation
During the filming of Batman & Robin, Warner Bros. was impressed with the footage they received. This prompted them to immediately hire Joel Schumacher to direct the next film, but screenwriter Akiva Goldsman, who had worked with Schumacher on Batman Forever and Batman & Robin, turned down the opportunity to write the script for the new film. In late 1996, Warner Bros. and Schumacher hired Mark Protosevich to write the script for the fifth Batman film. A projected release date was announced: mid-1999. Protosevich's script, titled "Batman Unchained," featured Scarecrow as the main villain, and, unlike the previous two films, it returned the franchise to a more serious and darker direction. 
The script explored Batman learning to conquer fear and confront the demons of his past.
The Joker returns as a hallucination in Batman's mind, caused by Scarecrow's fear toxin. Penguin, Catwoman, Two-Face, and the Riddler gather to judge the hero. 
Harley Quinn appears as the Joker's daughter, seeking revenge on Batman for her father's death. Crane discovers Batman's identity and forms an alliance with Harley to drive him insane and lock him away in Arkham Asylum.
According to the script, Robin leaves Batman due to differences, but returns during the final battle to aid his mentor. After defeating his enemies and demons, Bruce travels to Bali and finds himself in a cave full of bats, which fly around him as proof that he has conquered his fears. 
However, when "Batman & Robin" received negative reviews and flopped at the box office, Warner Bros. was no longer confident in its plans for a sequel, and George Clooney vowed never to don the Batman suit again. Joel Schumacher claimed he turned down the opportunity to return, declaring he had lost his "passion" for Batman in film and didn't want to turn that passion into work.
As a result, producer Peter McGregor-Scott was forced to film OnStar commercials featuring Bruce Thomas as Batman. The television spots reused surviving costume elements, such as Clooney and Kilmer's suits, as well as the Batcave set. The studio opted to bring back Michael Keaton's Batmobile and Danny Elfman's theme song to distance itself from Schumacher's two-part series.
Here are those spots:
Influence on Future Scripts
WB executive Greg Silverman was tasked with helping develop a new script featuring Scarecrow, written by Lee Shapiro and Stephen Wise, titled "Batman: Darknight." The new approach for the fifth film focused on physiological nuances and creating a more subtle, dark atmosphere. The budget was also more reasonable, addressing criticisms of the previous film. Ultimately, the studio decided that something completely different would be better suited for the fifth film.
As a result, Batman Unchained and a film adaptation of Frank Miller's graphic novel Batman: Year One were developed in parallel. Warner Bros. hired Darren Aronofsky to direct Year One. Realizing that the film deviated significantly from the source material, it was also abandoned. In 2003, Christopher Nolan proposed his vision, resulting in Batman Begins. The film's ending reveals numerous influences from both scripts, and also features the appearance of Scarecrow.
