In the midst of the Cold War, two young men discover their extraordinary powers for the first time. Charles Xavier, a telepathic and academic prodigy, crosses paths with Erik Lehnsherr, a Holocaust survivor with the ability to manipulate metal. Despite their differing backgrounds and ideologies, they share a common enemy: Sebastian Shaw, a former Nazi scientist and leader of the Hellfire Club, who has a dangerous agenda that threatens global security. Shaw possesses the power to absorb energy, rendering him almost invincible and he seeks to escalate tensions between the US and USSR to trigger a nuclear war, believing that conflict would advance mutant evolution.

As global political crises escalate, specifically the brewing conflict over missile deployment in Cuba, Xavier and Lehnsherr recruit other mutants to counter Shaw's plans. Among them are Raven, Xavier's adoptive sister who can shapeshift, and Hank McCoy, a brilliant engineer with ape-like feet. Xavier's team works to harness their abilities at his mansion, forming the bedrock for a unique academy. The group coalesces into an entity with a singular purpose: to stop Shaw and prevent a world war. Amidst training and strategy, Xavier and Lehnsherr form a deep bond, yet underlying tensions emerge, rooted in their differing perspectives on human-mutant relations and the future of mutantkind. These tensions sow the seeds for a larger conflict that parallels the external threat they've united to combat.