King Kull assaults the Rock of Eternity, leaving the inhabitants in a state of torpor. Only Mercury, the Roman Messenger of the Gods, escapes unscathed. The wizard, Shazam, telepathically communicates with Mercury, outlining a strategy to defeat King Kull. The Black Canary, and the Green Arrow, thwart a train robbery. Mercury steals the Green Arrow from the scene, then leaves the Green Arrow with the Justice League of America, and Hawkgirl. The Justice Society of America appear in the backseat of the Batmobile. Mercury touches the hood of the Batmobile, drawing the vehicle, and all it's occupants, across inter-dimensional space.
Mercury makes contact with Ibis the Invincible. Mercury then gathers Bulletgirl, Bulletman, Mister Scarlet, Pinky, the Whiz-Kid, and the Spy Smasher together. The Justice League of America, and the Justice Society of America meet the heroes of Earth-S. After being apprised of King Kull's scheme to destroy Earth-1, Earth-2, and Earth-S, the heroes split into three teams, to address the crisis. Mercury holds back Johnny Thunder, who is to embark on a special, solo mission. The Green Arrow, the Spy Smasher, Superman, and Wonder Woman journey to Earth-2.
There, they come into conflict with the Blockbuster, IBAC, the Penquin, and Queen Clea, on the risen continent of Atlantis. Superman attacks the Blockbuster, only to be beaten down. Superman continues his attack on the Blockbuster. Queen Clea straps the Girdle of Venus on Superman, placing the Man of Steel under her control. Superman resists Queen Clea's hold over him, managing to bar the Blockbuster from attacking Wonder Woman. Once Superman has beaten the Blockbuster into unconsciousness, he completely falls under Queen Clea's sway. Superman charges Wonder Woman.
Wonder Woman orders Superman to stop. Superman freezes mid-stride. Under the power of the Girdle of Venus, Superman is compelled to obey any order, not just Queen Clea's. Wonder Woman beats Queen Clea into unconsciousness. The Girdles of Venus are removed from the Blockbuster, and Superman. The Green Arrow, and the Spy Smasher, confront IBAC, and the Penguin. The two villains activate King Kull's doomsday weapon, before engaging the heroes. The Green Arrow gasses the Penguin. The Spy Smasher tricks IBAC into speaking his name, transforming the super-villain back into a meek street cleaner.
Superman follows the cloud released by King Kull's doomsday machine. The cloud hovers over an island, then, impossibly, increases the island's density until the island sinks. The cloud then moves off to the next land mass. Superman freezes the cloud with his super-breath, then hurls it into a passing comet. Earth-2 has been saved, but King Kull still has plans in place to destroy Earth-1, and Earth-S.