Gotham City is in the grip of a crime wave, with the police force struggling to contain the nefarious activities of gangsters and corrupt officials. The city finds hope in a mysterious vigilante known as the "Batman", a figure both feared and revered. Cloaked in the shadows, this elusive hero fights against the criminal elements that plague Gotham, using his physical prowess, detective skills, and an array of technologically advanced gadgets. While the public remains divided on Batman's role as a guardian or a vigilante, intrepid photojournalist Vicki Vale becomes intent on uncovering the man behind the bat-mask, seeing a profound story to be told.

Simultaneously, Jack Napier, a cunning and sadistic mob enforcer, falls into a vat of chemicals during a confrontation at a chemical plant. The accident leaves him with a permanent, grotesque rictus grin and an unhinged psyche. Adopting the name "The Joker", he ascends to the top of the criminal hierarchy and begins a reign of terror, aiming to rule the city through fear and anarchy. He becomes fixated on Vale, drawing her into a dangerous game, while his unpredictable behavior and penchant for theatrical crimes challenge Batman's efforts to stop him. As these two iconic characters are set on a collision course, Gotham's fate hangs in the balance, with the line between heroism and vigilantism blurred in their escalating conflict.