After manipulating ancient Pokemon DNA, a group of scientists inadvertently unleash Mewtwo, a powerful psychic creation bred for warfare with the aid of Team Rocket's resources. Mewtwo, realizing his grim purpose under Giovanni's control, rebels and establishes an island stronghold, inviting elite trainers like Ash Ketchum and his faithful Pikachu to face his wrath. Together, they must uncover Mewtwo's dark intentions and combat his overwhelming power before his quest for vengeance spells doom for both Pokemon and humanity.