Under a cloud of increasing anti-mutant sentiment, Professor Charles Xavier creates a safe haven at his Westchester mansion, where he could train young mutants to use their powers for the betterment of mankind. Aided by F.B.I. agent Fred Duncan, Xavier spends months recruiting his early students (code-named Cyclops, Iceman, Angel, Beast and Marvel Girl), dubbing them "The X-Men" because each possessed an "extra" ability which normal humans lack.