1970, Westchester New York City.Charles Xavier and Erik Lehnsherr stroll through a mansion, sharing their hopes for a future where mutants are accepted. Charles plans to open the mansion as a school for mutants. Thirty years later, Xavier's and Lehnsherr's school for gifted youngsters thrives, but societal fear of mutants leads the government to deploy scientist Bolivar Trask and his Sentinel program to capture mutants. The school’s X-Men team, comprising Bobby Drake, Warren Worthington III, Hank McCoy, and Jean Grey, is mobilized when they hear about quarterback Scott Summers' powers manifesting in Alaska. They rescue Scott and bring him to the school, where he learns about the other mutants' abilities and finds a sense of belonging.
The peace is shattered when a Sentinel attacks the X-Men at a mall, prompting them to defend themselves. Scott, inspired by Jean, emerges as a leader. Trask's Sentinels later assault the mansion, and the X-Men, now including a transformed Hank, fight valiantly. They defeat the Sentinels, but Trask arrives in a larger Sentinel, leading to a climactic battle where the team unites their powers to win. However, Trask injures Charles, leading Erik to kill Trask in retaliation. This act creates a rift between Charles and Erik, with Erik deciding to wage war against humanity. Weeks later, a paralyzed Charles reflects on the broken friendship with Erik, understanding the complexities of their shared dream.
