Batman discovers that his fiancée Julie Madison, while under a hypnotic spell, recently attempted a man's murder. Bruce takes her to see a therapist who recommends she take an extended vacation to France and Hungary - "the land of werewolves!" Determined to keep an eye on her, Bruce goes on the vacation voyage with Julie. On the boat, Batman finds Julie falling under another hypnotic trance. The man responsible for Julie's state is a masked figure known as the Monk. The Monk and Batman clash on the boat, and the Batman later chases him to a laboratory in Paris.