The Dark Knight Returns is set ten years in an alternate future, with a worn and weary, aged Bruce Wayne. He numbs his conscience with alcohol to soothe the guilt he feels for his responsibility for the death of Jason Todd. Gotham City is under siege by a vicious criminal gang who call themselves the Mutants. Wayne unleashes his demons to confront the new threats to Gotham, and Batman is born again. Wayne finds himself struggling with the decline of his physique as he patrols and defends Gotham City. An inexperienced but courageous young girl named Carrie Kelly saves Batman´s life, and Wayne takes her in as a new Robin.
Batman is seen now as a menace to Gotham´s society and an anti-vigilantism wave is carried on from the government. Even Commissioner Gordon became a victim of both, criminals and government as well after he killed a teenager in self-defense. He is replaced by Ellen Yindel, a well known anti-vigilante cop. Batman found out how the mutants gained their power and their high-tech weaponry - discovering a net of corruption inside the U.S. Army. Defeating most of the mutants, Batman faces the leader, however his advanced age became a disadvantage for him as is eventually incapacitated by the mutant leader. Fortunately, Carrie Kelly appears and rescues Batman, getting him the Batmobile. After initially mistaking him for Dick Grayson, Batman confirms Kelly as the third Robin. After his recovery, Batman and Robin lure the Mutants to a sewer dump ("the pipe), where Batman defeats the Mutant leader (released from prison by Commissioner Gordon) in hand-to-hand combat, effectively breaking the gang.
During the time Batman was gone, the Joker entered a state of catatonia, being unable to find something to live for. After Batman´s reappearance, the Joker woke up and convinced Dr. Wolper that he has been rehabilitated. When Wolper takes the Joker to a talk show, he begins a killing spree releasing his joker venom to the audience and kills Wolper as well. Batman appears to stop him, however the Joker escapes due to the fact that Batman had to struggle with the police. Batman and Robin began to search for the Joker, after he killed a group of boy scouts and Robin avoids more deaths after the Joker planted a bomb in a roller coaster. Batman paralyzes the Joker and faces a dilemma on whether if he should kill him or not. The Joker laughs and calls Batman a coward, he then snaps his own neck to blame Batman for his death.
Superman is called by the U.S. government to stop Batman after he returns from a mission in South America. A lethal group known as the Sons of Batman have been using deadly methods against criminals. Batman and Robin decides to train them to use non-lethal methods. During this time, Oliver Queen, formerly known as the Green Arrow, warns Bruce about Superman and the government plans. Batman eventually faces off Superman in crime alley. After a rough battle, Bruce seemingly gains the upper hand thanks to his prior preparation and Oliver's kryptonite arrow. With Superman knocked out by the effect of the kryptonite, Wayne lays down a final monologue on Superman regarding how he is "the one man who beat him". After that, he tricks Superman into believing he suffered a heart attack in order to be able to escape the government. Clark goes to Bruce's funeral where he hears a heart beat inside the coffin, and winks at Carrie. He then realizes that Wayne faked his own death. After this event, Wayne begins a new life with his "army": Robin and Green Arrow.
The Dark Knight Returns helped to re-define Batman and portray the character as he was originally conceived during the 1930's.