At a German concentration camp in occupied Poland in 1944, scientist Dr. Schmidt observes young Erik Lensherr bend a metal gate with his mind when the child is separated from his parents. In his office, Schmidt orders Lensherr to similarly move a coin on a desk, and kills his mother when the child cannot. In his grief and anger, Lensherr's magnetic power manifests, killing two guards and destroying the room, to Schmidt's delight. At a mansion in Westchester County, New York, young telepath Charles Xavier meets homeless young shape-shifter Raven. Overjoyed to meet someone else "different" like him, he invites her to live with his family.
In 1962, an adult Lensherr is tracking down Schmidt to take revenge. In England, Oxford University graduate Xavier is publishing his thesis on mutation; Raven, now his foster sister, lives with him. In Las Vegas, CIA agent Moira MacTaggert follows US Army Colonel Hendry into the Hellfire Club, where she sees Sebastian Shaw, Emma Frost, and Azazel. After Shaw threatens Hendry, Azazel disappears with the officer; moments later Hendry is in the War Room, advocating that the US install nuclear missiles in Turkey. 
Shaw later kills Hendry, revealing himself as Schmidt and demonstrating the energy-absorbing mutant power that has de-aged him.
MacTaggert, seeking Xavier's advice on mutation, convinces him and Raven to join her at the CIA, where they convince Director McCone that mutants exist and Shaw is a threat. The unnamed "Man in Black Suit", another CIA executive, sponsors the mutants and invites them to the CIA's secret "Division X" facility. Xavier locates Shaw, arriving in time to stop Lensherr, who had attacked Shaw, from drowning as Shaw escapes. Xavier brings Lensherr to Division X, where they meet young scientist Hank McCoy, a prehensile-footed mutant whom Xavier inadvertently outs as a mutant. McCoy, developing a bond with Raven, promises her he will find a way to normalize their appearance. Xavier uses a mutant-locating device, Cerebro, to find and recruit mutants for training to stop Shaw. He and Lensherr find stripper Angel Salvadore;
taxi driver Armando Muñoz, who takes the code name Darwin; Army prisoner Alex Summers, who calls himself Havok; and Sean Cassidy, who dubs himself Banshee. Raven takes the name Mystique. She also dubs Charles "Prof. X" and Erik "Magneto."
