The Hawkman charges an unseen foe, only to be cut down. Barely conscious, the Batman reaches for the Hawkman's emergency distress beacon, but collapses before activating it. Their attacker, an enormous automaton, activates the signal, to draw the Justice League of America to it, for elimination. Feeling isolated, Superman departs the Fortress of Solitude for the Justice League of America's satellite headquarters. There, Superman is surprised to find Zatanna on board. A year has passed since the Justice League of America, with the Elongated Man, aided Zatanna in recovering her father, Zatara.
Zatanna has come to celebrate that milestone. Their revelry is cut short by the Hawkman's distress signal. The Atom, the Flash, Superman and Zatanna follow the signal to Peru. There, they find the Batman and the Hawkman to, semingly, be suffering no distress. When asked about the enormous mining robot, the Batman reveals that it was uncovered by an archaeological expedition. Exposure to sunlight activated the automaton. Strangely, the automaton proved obedient to the Batman. Superman's super senses tip him off to the Batman's deceit.
The Green Lantern arrives, in response to the distress signal. Superman warmly greets their long-absent teammate, only to have the Batman shove him aside. The Batman angrily denies ever sending out a distress signal. The Atom questions the strangely silent Hawkman, who, timidly, backs up the Batman's claim. Using his x-ray vision, Superman proves to himself that the Batman, and the Hawkman, are not imposters. The Batman orders the team to leave, When they refuse, the Batman orders the automaton to destroy the Justice League of America.
Zatanna is the first to fall, followed by the Atom and the Flash. The Batman furiously rails on against his former teammates, while the Hawkman cowers on the ground. The automaton uses red sun radiation against Superman, while turning yellow to counter the Green Lantern's power ring. Ultimately, the automaton triumphs, declaring the Justice League of America terminated. Playing in to the Batman's induced madness, the automaton presents Superman's lifeless corpse to the Batman. With the Batman ranting like a madman, the automaton proceeds with it's primary mission.
The automaton sends a signal, into deep space, reporting on it's progress. The Green Lantern locks onto the automaton's signal, with his power ring, and beams the Atom along the carrier wave. The Atom cuts off all broadcasting systems to the automaton, disabling it. The Green Lantern reveals that the Justice League of America that confronted the automatons, were, themselves, also automatons. A precaution the Green Lantern advised, upon learning that the automaton was influencing the Batman. Superman takes the Batman, and the Hawkman, away, to get aid for their condition.
The Green Lantern, the Flash, and Zatanna join the Atom, on the alien world of Cam-Nam-Lao. The planet is a dead world. It's civilization long since collapsed. The automaton was being run, automatically, by still functioning computers. Cam-Nam-Lao was once ruled by powerful corporations, that annihilated one another in a nuclear holocaust. These corporations sent out massive automatons, into space, to gather minerals, and other resources, from other worlds. As the Justice League of America were attacked on Earth by once such automaton, so, too, were the heroes of the planet, Angor.
Now, said heroes arrive on Cam-Nam-Lao, immediately mistaking the Justice League of America, and Zatanna, to be responsible for launching the attack on Angor. The Justice League of America, and Zatanna, assume the same about the heroes of Angor. An epic battle ensues. While deflecting Jack. B. Quick's debris attack, the Flash propels a chunk of rubble at the Blue Jay. Zatanna urges the Green Lantern to throw up a protective energy shield, around the badly injured Blue Jay. The Green Lantern is forced to drop the shield, so that he can bring the full power of his ring to bear, to heal the Blue Jay. The Justice League of America make peace with the Heroes of Angor, who depart for their own world.