Superman calls the next meeting of the Justice League of America to order. The Green Arrow angrily pushes for the Justice League of America to get involved with socio-political issues. Suddenly, the Batman, the Flash, the Green Arrow, the Green Lantern, and Superman begin vibrating. Wonder Woman tries to get her Lasso of Truth around them, but the five heroes vanish. The five heroes are drawn across the dimensional void, arriving in orbit around Earth-Prime. The Green Lantern projects a protective force bubble around the Batman, the Flash, and the Green Arrow, before they asphyxiate in the airless void of space.
In the Australian outback, kangaroo poachers endure a violent encounter with Ultraa, the Ultimate Warrior. In Antarctica, a scientist, Anderson Carey, discovers a golden pyramid, buried in the snow. Contact with the pyramid incites a painful transformation in Carey. The Black Canary, the Red Tornado, and Wonder Woman are at a loss to explain their teammate's disappearance. Scanning Earth-Prime with his telescopic vision, Superman is astonished to find no trace of Metropolis, or Gotham City. Landing in Times Square, the Justice League of America encounter a group of bank robbers. The Justice League of America easily apprehend the bank robbers.
The Flash, finally, realizes that the Justice League of America are on Earth-Prime. The Justice League of America meet with Julius Schwarz, the editor of DC Comics. Schwarz theorizes that the population of Earth-Prime secretly possesses the ability to influence reality on Earth-1. Due to a recent popularity poll Schwartz conducted on the Justice League of America's membership, Schwarz further theorizes that focusing the masses concentration on the most popular Justice Leaguers drew them to Earth-Prime. The Flash attempts to bridge the dimensional abyss between Earth-Prime, and Earth-1, on a Cosmic Treadmill. Some force, however, prevents the Flash from bridging the gap.
A search party, sent out for Carey, is murdered, by the creature Carey has transformed into, Maxitron. The part of Maxitron that is Carey hungers for information. Maxitron reveals that millennia ago, a dying star went nova. One-third of the populace of an inhabited world, in orbit around that star, escaped destruction in an immense space ark. Maxitron was the computer brain that captained that arc. Nearing the planet, Pluto, the ark was caught in a meteor storm, that damaged it's guidance systems. The arc began a long, slow, plummet into the sun. One infant, among the arc's populace was selected for salvation.
That infant was rocketed to Earth, along with a caretaker cell, containing the computerized consciousness of Maxitron. En route to Earth, the caretaker cell struck a satellite, separating it from the infant, and causing it to fall to Antarctica. The infant landed in the Australian outback, where it was raised by Aborigines. Damaged, the caretaker cell's programming was compromised, and now believed it's primary function was to destroy the infant. The Green Lantern identifies, and locates, the origin point of the force holding the Justice League of America on Earth-Prime. The Green Lantern, and Superman head off to investigate.
A shockwave strikes the Batman, the Flash, and the Green Arrow. Too shook up to save himself from plummeting off the rooftop, the Flash just manages to rescue the Batman, before falling. The Green Arrow tags the Flash with a parachute arrow. Maxitron closes on the Justice League of America. The Green Arrow fires on Maxitron. The Batman just manages to evade Maxitron's weapon's fire. Maxitron takes out the Green Arrow. The Flash traps Maxitron in a super=speed generated whirlwind. Maxitron takes out the Flash. The Air Force attacks Ultraa. In defending himself, Ultraa is mistaken for the aggressor. Superman attacks Ultraa.
The Air Force attacks the Green Lantern. The Green Lantern easily destroys the jet fighters, without injuring the pilots. Superman subdues Ultraa, but realizes, too late, that Ultraa was not his enemy. On a Naval base, in Hawaii, the Green Lantern, and Superman speak with Ultraa. Maxitron arrives, threatening to murder the Batman, the Flash, and the Green Arrow, if the Green Lantern, Superman, and Ultraa do not surrender to Maxitron. The Batman, who has only been feigning unconsciousness, sends a message out to the three heroes. Maxitron analyzes the Green Lantern, Superman, and Ultraa, to learn their weaknesses.
The Green Lantern, Superman, and Ultraa are instructed to enter Maxitron's ship through three different doors. The Green Lantern is struck by yellow lasers, then attacked by an Osarian Tiger-Bear. The Green Lantern beats the bear into unconsciousness. Ultraa's hyper-sensitivity to sound is exploited, rendering him unconscious. Superman is burned by the solar rays of a red sun. Maxitron steps out to gather the fallen. Superman attacks Maxitron. Ultraa reveals himself to be wearing Superman's costume. Superman reveals himself to be wearing Ultraa's costume. Ultraa activates Maxitron's self-destruct system. Believing that Earth-Prime is still not ready for super-humans, Ultraa makes the journey, with the Justice League of America, to Earth-1.