The big city of Gotham City is plagued by gangsters, led by the acid-fuelled, horrifically disfigured Joker. The police seem helpless. Much more respectable among the criminals is the masked Batman - the Batman - appearing wherever mischief is being committed. Reporter Vicki Vale, covering Batman's stunts, meets shy millionaire Bruce Wayne and spends a heady night with him. The Joker tries to kidnap Vicki, but the girl is saved at the last moment by Batman. A journalist begins to suspect the truth. Wayne and Batman are one person. Meanwhile, the rampaging Joker terrorizes the city with poisoned cosmetics and challenges Batman to a decisive duel...