A new threat looms over San Fransokyo: Sunfire, a powerful and destructive antagonist with the ability to incite chaos with his fiery powers. He seeks to burn everything in his path, driving the world to the brink of destruction. However, there’s another, more insidious threat: a man calling himself "The Corruptor", a mysterious figure who manipulates minds (using Hiro's old microbot headband from the Professor Callaghan fight) and seeks to create an army of mindless zombies by turning Japan’s citizens into his pawns. As these two threats collide, Big Hero 6, Peni Parker, Moon Girl and Devil Dinosaur must stop them before their world is engulfed in flames and chaos. Meanwhile, they question whether or not free will is always a good thing.
