The techno organic race called the phalanx have been trying to assimilate mutants into their collective since their formation.   The mutant gene seems resistant to being absorbed, so the X-Men have been targeted for capture and termination.   While the X-Men are held captive the Phalanx try to make a run on Professor Xaviers list of young mutants who have just discovered their powers.  Banshee has the most ragtag of ragtag teams to help these kids before they are captured as well!