Synopsis
After going underground, Batman (Bruce Wayne) and his young sidekick, Catgirl (Carrie Kelly, Robin from Batman: The Dark Knight Returns), train an army of "batboys" to save the world from a "police-state" dictatorship led by Lex Luthor. In a series of raids on government facilities, Batman's soldiers release from captivity other superheroes including: The Atom (trapped for years in a petri dish), Flash (forced to run on a treadmill to provide America with free power), and Plastic Man (now insane and trapped in Arkham Asylum). Elongated Man is recruited from his job as a commercial spokesman and Green Arrow is already working with Batman (as seen in the end of The Dark Knight Returns).
Other heroes such as Superman, Wonder Woman and Captain Marvel have been forced to work for the government since their loved ones are being held hostage or are under threat. Superman is even ordered by the "President" (in fact a computer generated front for Lex Luthor and Brainiac) to stop Batman. He confronts Wayne at the Batcave, but is defeated by Batman and the other superheroes.
Meanwhile, Batman's raids have not gone unnoticed by the media. After being banned for years, the freed superheroes have recaptured the public imagination becoming a fad among youth. At a concert for the pop group "The Superchix", Batman and the other heroes make a public appearance, urging their fans to rebel against the oppressive government.
During this time, rogue vigilante The Question spies on Luthor's plans, typing a journal to record the misdeeds of those in power. He attempts to convince the Martian Manhunter (now an aged, bitter, near-powerless figure with his mind filled with Luthor's nanotechnology) to stand up against Superman and the powers that be. The two are soon attacked by a supernatural man resembling the Joker but who is seemingly invulnerable to injury, and the Martian Manhunter sacrifices his life as The Question is rescued by Green Arrow. The man escapes, but proceeds to kill other heroes such as The Guardian, Creeper and likely others who have come out of retirement, stealing and wearing their costumes in the process.
An alien monster lands in Metropolis and begins to destroy the city. Batman, however, is convinced that it is a way to lure him and his allies out of hiding and does not respond, callously dismissing Flash's claim that they are supposed to save lives. Batman's attitude is that the stakes are too high to worry about preserving life at all cost, whether this applies to men, women or even children.
Superman and Captain Marvel fight the monster, but it is revealed to be Brainiac, who coerces Superman (using the bottled Kryptonian city of Kandor as leverage) into losing the battle in order to crush the people's faith in superheroes. Captain Marvel is killed defending citizens from the carnage, but Superman is saved when Lara, his daughter by Wonder Woman, appears. She has been carefully hidden since birth, but, now that the government knows she exists, they demand that she be handed over.
Deciding that Batman and his methods are the only way, Superman, Wonder Woman and their daughter join him. By having Lara pretend to hand herself over to Brainiac, the Atom is able to slip into the bottle and free the Kandorians who use their combined heat vision to destroy Brainiac, the heroes subsequently destroying the power source of the dictatorship and inciting revolution. Batman allows himself to be captured and tortured by Luthor in order to learn his plan: Luthor has launched satellites to destroy most of the world's population and leave them with a more manageable number of people. The satellites are destroyed by the now god-like Green Lantern who wraps a giant fist around the Earth, destroying Luthor's several trillion dollars-worth of weapons. Luthor is subsequently killed by the son of Hawkman, whose parents had been killed earlier on. This is an action Batman planned and approves, much to Flash's horror.
Returning to the Batcave, Batman receives a communication from Carrie: she is being attacked by the Joker-like man, now wearing a Robin costume. Batman arrives and recognises the man as Dick Grayson, the first Robin, who Batman fired long ago and who has now been genetically manipulated to possess a powerful healing factor and shapeshifting ability, but has also been driven criminally insane. As Batman and Dick contemptuously go over their bleak history together, Batman drops him via a trapdoor into a miles-deep crevasse filled with lava while Elongated Man gets Carrie to safety. Dick clings onto a ledge and climbs out of the chasm to face Batman personally, and when Dick remains virtually unharmed by everything Batman throws at him, Batman takes drastic measures and hurls himself and Dick into the chasm. While Dick falls into the lava and is completely disintegrated, Superman rescues Batman at the last minute as the cave blows up, and takes him to Carrie in the Batmobile. She laments the loss of the cave and all of Batman's memoirs, but Batman remarks that they are just souvenirs, and tells her, "I was sentimental, back when I was old."
Read more about this topic: The Dark Knight Strikes Again