Batman, the caped crusader, operates as a vigilante in crime-ridden Gotham City. Although police do not acknowledge his existence, journalist Alexander Knox publishes a story about him in the Gotham Globe, enduring the ridicule of his fellow newspapermen, who believe Batman is a myth. However, a beautiful photographer named Vicki Vale approaches Knox at his desk, reveals that she shares his enthusiasm for the Batman story and presents her latest work, photographs of a foreign war that recently made the cover of Time magazine. Knox eagerly agrees to work with Vicki, who suggests they start by attending a benefit held by local businessman, Bruce Wayne. Meanwhile, Carl Grissom, head of Gotham’s crime syndicate, worries that newly elected district attorney, Harvey Dent, plans to investigate Axis Chemical Co. Since Grissom’s syndicate has ties to Axis, Grissom sends his underling, Jack Napier, to raid company files before police get to them. Napier, who is secretly having an affair with Grissom’s mistress, grudgingly follows orders. That evening, at Bruce Wayne’s mansion, Knox attempts to glean information about Batman from Police Commissioner Gordon and Harvey Dent, while Vicki seeks out the party’s host, who eventually reveals himself and confesses he is a fan of her photography. Grissom betrays Napier by calling in an anonymous tip to the police, and Gordon gets word that Axis Chemical is being raided. The commissioner rushes to the scene with Police Lieutenant Eckhardt and a team of policemen. As they arrive, a shootout ensues, and Napier releases toxic chemicals to stave off his pursuers. Batman appears and captures Napier, but Napier’s man, Bob the Goon, holds Gordon at gunpoint, forcing the caped crusader to release his captive. Napier shoots Lt. Eckhardt, then fires at Batman, who deflects the bullet back to his attacker’s face. Napier falls into a vat of chemicals and the police leave him for dead. Later, as Knox attempts to cover the story, police claim Batman was never there, but Knox is unconvinced. Vicki accepts an invitation to dine with Bruce Wayne, and the two forgo his formal dining room to eat in the kitchen with Albert, Bruce’s butler and trusted confidant. That night, in a makeshift operating room, a doctor performs surgery on Napier’s mangled face, and the gangster laughs hysterically when he sees his reflection in the mirror. Aware that he was set up, Napier surprises Grissom at his office and reveals his new look: green-tinted hair, a chalky, white face, and a permanent, grotesque grin painted red. Still laughing, Napier instructs Grissom to call him “Joker,” then shoots the man dead. After waking up in Bruce Wayne’s bed, Vicki tries to arrange a second date, but Bruce claims he must leave town. Meanwhile, Napier’s new alter ego, the Joker, leads a crime syndicate meeting and announces Grissom has gone away and left him in charge. He kills Tony, one of the syndicate men, and his henchmen usher the others away at gunpoint. Suspicious that Bruce lied to her, Vicki follows him into town and observes as he leaves two red roses on the sidewalk in front of a shuttered hotel. At the Gotham City courthouse, Vinny, one of the syndicate members, files an affidavit for control of Grissom’s holdings, and a crowd forms outside as Knox questions him. Bruce gets there just before the Joker and his henchmen arrive. Marching up the courthouse steps, the Joker kills Vinny with a poisoned pen, then escapes in a car. Later, Bruce informs Albert that Napier is still alive and has taken control of Grissom’s operation. He requests police files on Napier, and learns that the gangster has a history of violence and psychological problems, as well as an interest in chemistry. At the Axis plant, the Joker oversees production of new chemicals, and soon, women begin dying with wide grins on their faces from poisoned cosmetics. Despite the rash of deaths, Gotham’s mayor insists that a 200th anniversary celebration for the city will go on as scheduled. Meanwhile, after seeing a photograph of Vicki in the courthouse crowd, the Joker decides to make her his next girl friend and lures her to a museum, where she believes she is meeting Bruce. As she waits at a table, Vicki receives a box containing a gas mask and a note instructing her to wear it. Suddenly, toxic gas spills into the museum, incapacitating everyone but Vicki. The gas clears and the Joker marches in with his goons, who deface paintings and sculptures at his instruction. He asks Vicki about Batman, but she claims to know nothing. Batman crashes in through the ceiling, rescues her, and drives her away in his heavily armored Batmobile. However, they are forced to proceed on foot when the vehicle crashes. The Joker’s henchmen catch up to Batman, but when they shoot, they discover he is protected by body armor. As Batman fights off his attackers, Vicki secretly snaps photographs. Afterward, he retrieves the Batmobile and leads her to his headquarters in a cave outside the city. Batman shares his findings that the Joker has poisoned hundreds of cosmetics, but the poisoning effects only take hold when certain components are mixed, like hairspray with lipstick and perfume, and provides her with a report to be printed in the Gotham Globe. The next morning, Vicki discovers that Batman stole the film from her camera, but, with the help of Knox, she gets Batman’s story printed on the front page. Unaware that he is Batman, Vicki reprimands Bruce for not returning her calls when he comes to her apartment later that day. He attempts to explain his dual identity, but they are interrupted by the Joker, who aims his gun at Bruce and asks if he “ever danced with the devil in the pale moonlight.” Bruce recognizes the phrase, but crumples to the ground when the Joker shoots him. Vicki rushes to Bruce’s aid but finds him gone, realizing that he used her silver tray to stop the bullet. At the Gotham Globe offices, Knox shows Vicki a newspaper clipping about the murder of Bruce’s parents, which he witnessed as a child, and she deduces that the scene of the crime was the spot where Bruce left the roses. In a televised announcement, the Joker tells Gotham’s citizens that he will drop twenty million dollars on the streets at midnight as part of the 200th anniversary celebration, and challenges Batman to a duel. Meanwhile, Bruce looks at the newspaper clipping of his parents’ killing and recalls the shooter asking, “You ever dance with the devil by the pale moonlight?” Bruce suits up as Batman and drives the Batmobile into Axis Chemical Co., where he drops a bomb that destroys the plant. At midnight, the Joker enters Gotham City on a parade float and throws money on the crowd as promised. However, several large balloons tethered to the float release poisoned gas, causing revelers to drop to the ground, lifeless. There to cover the story, Knox orders Vicki inside his car and dons a medical mask as he attempts to fight off the Joker’s goons. Batman flies over the city in his airplane, the Batwing, collecting the poison-filled balloons and sending them into the upper atmosphere. Angry over the stolen balloons, the Joker shoots Bob the Goon dead, then fires at the Batwing, causing it to crash into a church. Vicki rushes to the Batwing, but the Joker kidnaps her and leads her inside the church. Batman emerges from the crash and follows them into a stairwell leading to the belfry. Joker releases one of the bells, which crashes to the first floor and blocks police from entering. However, Batman continues his pursuit and faces off with several of Joker’s henchmen before tussling with the Joker himself. Although Batman knocks him over the side, the Joker lands on a ledge and pulls Batman and Vicki over. As they dangle from the ledge, a helicopter arrives to rescue the Joker, who takes hold of a rope ladder dangling from the aircraft. Batman uses his grapple gun to shoot wire around Joker’s ankle. The other end of the wire is tied to a gargoyle that breaks off the belfry as the Joker is pulled away, but the weight of the gargoyle causes the archvillain to lose his grip, and he plummets to his death. Later, Harvey Dent holds a press conference and reads a letter from Batman, who promises to fight the forces of evil if they return to Gotham City. Dent also reveals a bat-shaped spotlight Batman provided for police to call on him. Viewing the spotlight with a smile, Vicki greets Albert, who awaits her with a car and informs her that Bruce will be a little late for their date.