Nuclear war throws the entire world into Armageddon. The resulting conflict is a geological upheaval of unprecedented horror. Entire populations are wiped out and the radiation from the nuclear fallout robs Earth’s heroes and villains of their super-powers.
One of the few survivors is Clark Kent. Alone and powerless, he buries those closest to him in the ruins of Metropolis including Lois Lane, Jimmy Olsen, Perry White and Bruce Wayne.
Clark ekes out a life for himself, often having to defend himself from giant-sized rats and atomic mutants. He domesticates a giant cat and names him Kryptonite.
Years pass, but one day, while foraging through the jungle, Clark discovers another survivor – Wonder Woman. The two are overjoyed to find one another and Wonder Woman brings him back to the city of Champion – a jungle refuge housing others who survived the holocaust including the Flash, Guy Gardner, Mister Miracle, the Cheetah and Joker, all of whom have been de-powered, and, in the case of the Joker, rendered sane. Of the survivors only the adult Bill Batson is underwhelmed at Superman’s appearance. Before the war, Batson always felt like he was playing second fiddle to Superman, and now it seems as if history might repeat itself.
The people of Champion build their cities and continue their constant struggle to survive against the forces of the invading mutant population. Superman and Wonder Woman become close to one another and eventually fall in love. This enrages Batson, who once had a relationship with Wonder Woman.
When no one is around, Batson goes into the jungle and invokes the name, “Shazam”, calling down the mystic lightning. The lightning transforms him into Captain Marvel, but the surge of power is only temporary, and in minutes, it fades away.
Superman and Wonder Woman are married and have a child together whom they name Bruce.
Bill Batson continues to call down the magic lightning. Each time he does so, the lightning slowly restores the heroes’ powers, but only in incremental stages. None of them realize this is happening. They further don’t realize that every time Batson summons the lightning, it is causing massive instability to the entire planet.
Batson’s rage and jealousy overwhelm him. He turns on the people of Champion and heads out west. He finds another survivor, Metallo, and recruits him to a new cause. Batson and Metallo side with the mutants and decide to betray the people of Champion. During a massive battle, the Martian Manhunter and Wonder Woman are killed. Batson takes great delight in personally taking Wonder Woman’s life.
Enraged, Superman fights Captain Marvel at the top of an active volcano. Whatever mysterious presence exists that bequeaths power to Captain Marvel betrays him, and a powerful lightning bolt strikes downward, killing him. Superman dumps his body into the volcano.
Superman now realizes that the geological upheavals that have been developing over time will now consume the entire planet. Using a power ring from a late Green Lantern, he creates an energy construct rocket ship for his son, Bruce. Bruce Kent rockets off into outer space leaving Clark behind as both the Last Son of Krypton and the Last Son of Earth.