Trama

In Gotham City, Batman (Val Kilmer) saves a guard from Two-Face, the alter ego of the disfigured former district attorney, Harvey Dent (Tommy Lee Jones). Flashbacks reveal that Batman failed to prevent Dent's disfigurement with acid by mobster Sal Maroni, causing Dent to develop a split personality, make decisions based on the flip of a coin, and swear vengeance against Batman.

It was the second anniversary of Dent's accident, and he has held the guard hostage to lure Batman. The guard was held inside a giant safe and as soon as Batman enters it, the door snaps shut. Batman and the guard are locked in a safe tied to a helicopter, where it is filled with acid. Using the security guard's hearing aid, Batman unlocks the safe. Batman returns the safe and goes after Dent. Dent kills the helicopter's pilot and both Dent and Batman flee from the ensuing explosion as the helicopter crashes into the Statue of Liberty. Two-Face manages to escape with a parachute, while Batman jumps into the water.

Commissioner Gordon (Pat Hingle) and The Mayor (George Wallace) work with Batman to eliminate crime from the city. Two-Face is served by 2 assistants. Sugar (Drew Barrymore) Two-Face's "good" angelic-like assistant. She has short, blonde hair and wears a white corset bodysuit with stockings and a fluffy white robe. Spice (Debi Mazar) is Two-Face's "bad" gothic-like assistant/girlfriend. She is clad in a black leather corset with fishnet stockings on her legs with shiny black latex heels and long black leather gloves and appears as of a dominatrix.

Meanwhile, Wayne Enterprises researcher Edward Nygma (Jim Carrey), develops a device to beam television directly to a person's brain, demanding immediate approval directly from Bruce. Nygma gets a chance to show the device to Bruce during his inspection of the Electronics division of his company. Bruce Wayne rejects the invention as he is irritated by Nygma and is concerned that the technology could manipulate minds as it tampers with brain waves. Nygma's supervisor Fred Stickley (Ed Begley Jr.) attempts to terminate the project. Nygma tests the machine on his supervisor and kills him when Fred threatens to report Nygma to the FCC for illegal human experimentation. Nygma resigns and plots revenge against Bruce, sending him riddles.

Chase has a huge crush on Batman, and even summons him for a late-night meeting using the bat signal. Bruce meets psychiatrist Dr. Chase Meridian (Nicole Kidman) regarding the riddles left for him trying to understand the mental state of the person. Criminal psychologist Chase Meridian diagnoses the person as psychotic.

Bruce invites her to a charity circus event. Two-Face hijacks the event and threatens to detonate a bomb unless Batman reveals his identity. The youngest member of the Flying Graysons and acrobat Richard "Dick" Grayson (Chris O'Donnell) manages to throw the bomb into a river, but Two-Face kills his family in the process.

Assuming responsibility for Dick, Bruce allows him to stay at Wayne Manor. Dick declares his intention to kill Two-Face and avenge his family's murder, and when he discovers Bruce's secret identity as Batman, he insists on becoming his partner. Bruce, however, turns Dick down. Despite his master's wishes, Bruce's loyal butler Alfred (Michael Gough) provides guidance and counsel to Dick related to his desire to follow Bruce's path.

Nygma, meanwhile, becomes the Riddler, allying with Two-Face and promising to discover Batman's identity, he sends Bruce two additional riddles. They commit a series of robberies to finance Nygma's new company and mass-produce his brainwave device dubbed the Box, which steals information from minds and transfers it to Nygma's. Having become popular, Nygma's device, the Box, has a unique side-effect allowing him to access its users' brainwaves and enabling him to discover every secret they possess, enhancing his own intelligence and knowledge in the process, but also slowly causing him to lose his grip on reality.

Unveiling an advanced device at a business party, Nygma is able to discover Bruce's secret identity. Two-Face attacks the party and nearly buries Batman alive, but Dick saves his life. Continuing to turn down Dick's offer, Bruce gives up his post as the Dark Knight to discourage Dick, and pursues a relationship with Chase, whom he plans to tell his secret to.

Disheartened by Bruce's plans, Dick takes his leave. However, Two-Face and the Riddler later infiltrate Wayne Manor on Halloween just after Bruce has revealed his identity to Chase. The Riddler enters the Batcave and destroys most of the equipment, and he and Two-Face kidnap Chase after Bruce is grazed on the head by a gunshot from Two-Face, though the Riddler stops Two-Face from killing him. They also leave Bruce a final riddle and detain Chase in the Riddler's lair.

After solving the last riddle and using all the answers to determine who Riddler is, Bruce dons his only surviving Batsuit and prepares to confront his enemies. When Dick returns in a costume made by Alfred, telling Batman his stage name is "Robin", Batman finally accepts him as his partner.

Batman and Robin locate the Riddler's lair, where the two are separated upon reaching the island. Robin engages Two-Face in a duel, nearly knocking the villain to his death. Robin shows mercy and aids Two-Face but is taken hostage. Batman is able to successfully infiltrate the tower, whereupon the Riddle reveals Robin and Chase are both held hostage, bound and gagged in giant jars above a pit of water and metal spikes.

Chase and Robin, representing the two sides of Batman's personality, are trapped in tubes above a deadly drop, and he only has the time to save one. Batman distracts the Riddler with a riddle himself, before destroying the Riddler's brainwave receiver with a Batarang, damaging the Riddler's mind and enabling Batman to rescue both when he sees the floor is an optical illusion.

Batman is able to rescue Robin and Chase from falling to their deaths, only to find Two-Face holding them at gunpoint. Two-Face corners them and flips his coin to decide their fate, but Batman throws a handful of identical coins in the air, causing Two-Face to fall to his death.

The Riddler is sent to Arkham Asylum, and Chase is asked to consult on his case. Riddler offers to reveal the identity of Batman to her, only to claim that he is Batman, showing he has truly become insane. Chase tells Bruce his secret is safe, and they kiss before Chase departs.