Spider-Man's progressing neogenic mutation is making him ill and he seeks the aid of a man known to help all mutants, Dr. Charles Xavier. In doing so he meets the X-Men, but is disappointed to learn that Xavier does not 'cure' mutancy, only helps those born that way to accept and control their abilities. In the process of this endeavor he becomes involved in a plot to destroy mutants everywhere, and must stop this hideous plan with the help of the X-Men.