The X-Men and the Brotherhood of Mutants must deal with the consequences of their identities being revealed and the destruction of the mansion. As the world comes to now of mutants the children face all new challenges in the world and high school. They would encounter the Morlocks (including Caliban, Facade, Leech, Lucid, Torpid, and their leader Callisto), a group of underground mutants too deformed to exist among normal humans. Spyke would eventually join when his powers went out of control. Wolverine would learn that he has a female clone named X-23. They would also have to deal with Mesmero, a powerful psychic mutant who seeks to unleash the very first mutant, Apocalypse.