When Cyclops and Nightcrawler save people from a car crash they question Xavier's desire to keep their identities a secret. Meanwhile, the Brotherhood terrorize people in a crowded stadium.

Avalanche wants to join the Institute, but has trouble being accepted by the others, especially after he's accused of taking joyrides on the X-vehicles at night.

The women form a team of crime fighters after Jean and Amara are teased for having weaker powers, and they call themselves the Bayville Sirens.

Mystique frees a mutant called the Scarlet Witch from an asylum, hoping she'll help the Brotherhood, but Mystique doesn't know the witch is seeking revenge on Quicksilver and Magneto.

At Xavier's urging, the Brotherhood and the X-Men unite to battle Magneto; and the Institute begins to self-destruct while students are trapped in the mansion.

A traitor in the battle threatens the efforts of the X-Men and the Brotherhood against Magneto, who has another secret weapon--the Sentinel robot.

The X-Men and the Brotherhood rally after the mansion's destruction, and they try to find Xavier and the captured X-Men.

Wanda searches for Magneto while Toad steals Nightcrawler's holo-image inducer, hoping that, if he changes his appearance, he'll win over the Scarlet Witch.

Wolverine learns that he's been cloned by HYDRA scientists, and the clone targets Logan.