At Gotham State Penitentiary in the presence of Batman, Robin, and District Attorney Harvey Dent, Dr. Hugo Strange and his assistant Dr. Harleen Quinzel carry out an experiment on five selected inmates; Joker, Penguin, Riddler, Egghead and Mr. Freeze in an attempt to remove their evil with a machine called the Evil Extractor. The experiment goes wrong and Harvey is exposed to the gas from the Evil Extractor’s collection vat, scarring the left side of his face, despite Batman’s intervention. The effects of the gas causes Harvey to become Two-Face as he becomes a player in the Gotham City underworld. Now Batman and Robin must work to defeat Two-Face.