

Harley, who has escaped from Green Arrow and has decided to become a hero, releases the inmates, forcing Batman and Superman to temporarily put their differences aside to fight them. While trying to stop Superman from relocating Arkham Asylum inmates to a more secure facility, Batman and Nightwing are shocked to discover that Robin has joined Superman. Later, Superman visits Batman in the Batcave to make peace, but they get into an argument over their ideological views, and Batman rejects Superman.

Elsewhere, Batman confronts the President and warns him that Superman will kill him if he finds out he ordered Jonathan's capture. Confronting Mirror Master, Wonder Woman learns Jonathan's whereabouts and takes his belt, which Superman uses to find and rescue his father. Superman begins to question his actions, but Wonder Woman reassures him that he is doing the right thing and offers to help him find Jonathan. Meanwhile, the United States government, concerned that Superman will interfere in their operations, orders Mirror Master to kidnap Jonathan Kent as leverage against him. Some heroes, such as Aquaman and Shazam, refuse to choose sides and leave the League. The Justice League is left divided over Superman's actions, as some members, such as Wonder Woman, believe in his cause to eliminate violent criminals, while others, including Batman, keep their no-killing vow. While Green Arrow takes Harley to his hideout to protect her from Superman's wrath, Superman reveals his identity before the United Nations and announces his intentions to bring peace to Earth, by force if necessary. Moments later, Superman arrives and, acting out of grief and rage at the loss of his wife and unborn child, murders the Joker in cold blood. Under Batman's interrogation, Joker reveals that he had grown tired of his losing battle against Batman and sought to try and corrupt Superman instead. Batman tries to warn Superman, but it is too late Lois' heartbeat stops, and the nuke detonates, destroying Metropolis and killing millions of people. As the other heroes arrive and apprehend the Joker and Harley, Batman analyzes the gas revealing it to be fear toxin mixed with Kryptonite, and was used to make Superman hallucinate into thinking that he is fighting Doomsday in reality, he has killed Lois. Superman eventually finds the Joker and Harley hiding on a submarine, but when he confronts them, he is seemingly attacked by Doomsday and proceeds to punch the monster into space. The Flash finds the Scarecrow dead in his lab and his supply of fear toxin missing, before being killed by a trap laid by Joker. Upon hearing of Lois' capture, Batman calls in all Justice League members to find her. However it is short lived as Lois follows up on a lead with Jimmy and ends with the Joker and Harley Quinn killing Jimmy Olsen, and kidnapping Lois Lane, and they also steal a nuclear weapon, which they connect to a heart rate monitor surgically attached to Lois' heart. On Earth-22 the day starts out ordinarily, the heroes are saving people and Clark Kent is having a happy life with Lois Lane. This unnhinged Superman decides to take control of Earth for its own good, leading Batman and his allies to attempt to stop him. The story takes place on an alternate Earth in which the Joker has tricked Superman into killing Lois Lane, sending the hero on a rampage.
