The detective Batman, and his sidekick Robin, are on a new case involving people dying with disfigured grins on their faces. Batman and Robin realize that the killer is Alfred Stryker, a criminal now disfigured with a permanent grin, green hair and pale white skin, now going by the name of the Joker. When he seduces a psychiatrist to become his partner-in-crime, Batman and Robin must stop them from killing all of Gotham City with a dangerous toxin, all while trying to maintain their partnership.
