In Metropolis, a pregnant Lois Lane is kidnapped by Joker. While Superman searches for her, Batman and the Justice League deduce that Joker has used Scarecrow’s fear toxin and laced it with stolen kryptonite to affect Superman. Superman and the League track Lois to a submarine where Joker and Harley Quinn are hiding, but Superman is attacked by Doomsday. He fights and defeats Doomsday, only to learn Doomsday is an illusion and he has been fighting an unconscious Lois. Too late, he learns that Lois's heart was synched to a nuclear warhead, which detonates and destroys Metropolis when her heart stops. Blinded by grief and revenge, Superman kills Joker, despite Green Lantern’s and Batman's best efforts to stop him.
A grieving Superman decides that all violence must end, by force if necessary.
