As a result of Brainiac's manipulation over Lex Luthor, the conflict between Heroes and Villains has escalated to war. As a result the city of Metropolis has been reduced to ruins as the last remaining forces of the Justice League of America and the Secret Society of Super-Villains face off for one final battle.
Following the defeat of both groups and Brainiac's total conquest of Earth, two of the planet's sole remaining freedom fighters travel back in time to alter the events that transpired to bring about this future.
Superman has left Earth to recharge his powers at the Sun. During the climactic battle in the ruins of Metropolis, Lex Luthor captures Wonder Woman and tells her to call him. After her refusal, Luthor blasts her with an electrical bolt, causing her to scream. In space, Superman hears Wonder Woman's cry and goes to her aid. After burning Black Adam's face with a heat vision blast and throwing Luthor away, Superman goes to Diana's side, only to find her mouth stuffed with kryptonite. Badly weakened, Superman is unable to defend himself when Luthor recovers and stabs him with a kryptonite-tipped spear, killing him instantly. Lex is unable to celebrate his victory, however, as not even seconds after the Man of Steel's death does Brainiac's invasion force arrive.