When high-schooler Todd Tolanski starts exhibiting toad-like mutant powers, Mystique sees a perfect opportunity to get a spy into Xavier's institute. Meanwhile the X-Men recruit a new member as Kurt Wagner joins Xavier's school.
When Kitty Pryde discovers her mutant ability to phase through objects, Xavier sends Jean Grey on a mission to recruit her. Meanwhile, Wolverine's arch-nemesis, Sabretooth rolls into town and he's looking for a fight.
In Mississipi, a girl known only as Rogue learns she has power to absorb the memories, energy and powers of others. This frightens her, but also leads to both the X-men and the Brotherhood trying to find her for their own purposes.
A large mutant boy, Fred 'Blob' Dukes, enrolls in Bayville High. It is soon apparent that Fred has many issues deal with including his powers and his feelings about Jean.