Set during the 1950s, the plot follows the aftermath of the Korean War as America and the world grapple with political tensions and the looming threat of nuclear annihilation. In this troubled time, a mysterious and ancient cosmic entity known only as "The Centre" plans to eradicate humanity. Against this backdrop, various iconic superheroes such as Superman, Wonder Woman, and Batman exist but face societal mistrust and growing disillusionment with the American government. Hal Jordan, a Korean War pilot, grapples with his pacifist leanings even as he is pulled into a secret space program. Meanwhile, J'onn J'onzz, the Martian Manhunter, accidentally arrives on Earth, struggling to find his place among humans while hiding his true identity.

As these heroes and several others navigate their personal dilemmas and moral ambiguities, their paths converge when they begin to uncover The Centre's plan. The entity's influence becomes evident through strange phenomena and escalating violence, forcing the heroes to confront the imminent disaster. However, personal challenges and mutual distrust among them threaten their ability to work together. The emergence of new heroes, such as Barry Allen as The Flash, signals a new era of collaboration, but the combined effort needed to tackle The Centre's catastrophic threat tests their resolve and unity. As the tension builds, the heroes must transcend their differences to save humanity from impending doom, setting the stage for an epic confrontation that will redefine their role in a new frontier.