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There's a moment in X2 where Scott very nearly blasts the door to Magneto's plastic prison. If Lady Deathstrike hadn't gotten the drop on him first, not only would he not have spent the rest of the movie as MindControlled!Scott, but things might have gone very differently for both the Brotherhood of Mutants and the X-Men.
In Freefall, after an impromptu prison break, Scott and Charles join forces with Magneto and Mystique to find the other X-Men and stop Stryker's plans before time runs out for mutants everywhere. But old and new tensions run high in this uneasy alliance, and the real challenge may be working together without anyone falling apart.
Chapter One: In Case of Emergency, Break Glass
Chapter Two: With Enemies Like These
Chapter Three: Stree Fractures