Two years after the events of M3GAN, Gemma has become an author and an advocate for regulation of artificial intelligence while trapping a still-active M3GAN in a small, harmless robotic doll. However, M3GAN's technology has been stolen and used by a defense contractor to create a military robot called AMELIA (autonomous military engagement logistics and infiltration android), who becomes self-aware, turns on her creators, and attempts an AI takeover. Facing imminent destruction, Gemma's niece Cady convinces her to rebuild M3GAN with advanced upgrades so she can fight AMELIA
