Joker (The Dark Knight)

No one knows who the Joker really was, and little could be confirmed about his early life before he turned to a life of crime.^[5][6][7] Despite his capture, no traces could be found on his fingerprints, dental records, or DNA matches in the Gotham City Police Department's databases.^{[8][9][10][11][12]} His testimony was contradictory, as he gave multiple conflicting accounts of how he got the scars of his Glasgow smile.^[13][14] In one account, he described having an alcoholic and abusive father who carved his face with a knife after attacking his mother.^[15] In another, he claimed to have mutilated his own face with a razor to resemble his wife after she was disfigured by loan sharks.^[16] These accounts were fabricated to manipulate and confuse his victims.

Shortly after the collapse of the League of Shadows following the death of Ra's al Ghul, Bruce Wayne / Batman discusses with police lieutenant James Gordon the effect that he has made on Gotham City since his appearance. The Joker was then mentioned when Gordon reveals that a criminal with a "taste for the theatrical" has recently committed a double homicide and an armed robbery,^[17] and leaves behind a Joker playing card as a "calling card".^[18] Gordon also warns that, just as escalation occurs in terms of a police force against crime, so might the scale and style of criminality change in reaction to Batman's appearance.^[19]

Several months later, under the direction of the Joker, a clown-masked group of bank robbers carried out a heist on Gotham National Bank, which was used by various mafia families as a front to launder money. The robbers eliminated each other in a series of planned betrayals until only "Bozo" remained,^[20] who revealed himself to be the Joker.^[21] He exposed himself on a surveillance camera before escaping with the stolen money in a school bus.

Following the robbery, the Joker confronted Gotham's crime lords, including Salvatore "Sal" Maroni, Gambol, and the Chechen, during a meeting regarding their finances. He proposed killing Batman in exchange for a share of their money and warned them about corrupt Chinese accountant Lau's potential betrayal. After killing one of Gambol's henchmen during the meeting, he revealed grenades hidden under his coat to ensure his escape, leading Gambol to place a bounty on him.

The Joker later retaliated against Gambol by deceiving his men and ambushing him. He recounted one of his conflicting origin stories while holding Gambol at knifepoint before killing him. He then compelled Gambol's remaining men to fight each other for a place in his gang, consolidating his control over them.

The Joker eventually learns that Batman had captured Lau from Hong Kong and that the police had struck a deal with him to testify against the mob. This revelation prompts Sal Maroni and the Chechen to accept the Joker's offer and hire him to kill Batman in exchange for half of their money. To begin his campaign, the Joker kidnaps a Batman impersonator, records his murder, and displays the body outside City Hall, accompanied by a video message sent to the media in which he mocks the victim and issues a public threat. He delivers an ultimatum to Gotham City: Batman must reveal his identity, or innocent people will be killed each day. When Batman refuses, the Joker targets individuals connected to district attorney Harvey Dent's prosecutions, murdering Judge Janet Surrillo with a car bomb and poisoning Commissioner Gillian B. Loeb, establishing a pattern of escalating violence designed to pressure both the city and its protector.

The Joker later attacks Bruce Wayne's penthouse during a fundraiser in an attempt to locate and kill Harvey Dent. When the guests refuse to cooperate, he threatens their lives and targets Rachel Dawes, but is interrupted by Batman. During the confrontation, the Joker throws Rachel out of a window, forcing Batman to save her and enabling his escape, while he begins to suspect that Dent may be Batman. Continuing his campaign, the Joker orchestrates an assassination attempt on Mayor Anthony Garcia during a memorial for Commissioner Loeb by disguising himself and his accomplices as honor guards. During the ceremony, the Joker uses a sniper rifle to fire upon the podium. The attack results in James Gordon faking his death while protecting the Mayor in order to operate covertly.^[22] In response to the escalating threat, Dent publicly claims to be Batman in an effort to stop the killings, leading to his arrest.

While Harvey Dent was being transported to the GCPD, the Joker and his gang hijacked an 18-wheeler and attacked the police convoy with heavy weapons in an attempt to kill Dent, destroying most of the escort vehicles. Batman intervened, using the Tumbler to intercept an RPG attack and deploying the Batpod. Realizing Dent was not Batman, the Joker instead engaged Batman directly and attempted to provoke Batman into killing him, but Batman refused and ultimately crashed. Before the Joker could unmask him, James Gordon—who had faked his death—reappeared and arrested him, leading to his promotion to commissioner.

While in custody, the Joker revealed that Dent and Rachel Dawes had been kidnapped and placed in separate locations rigged to explode, as part of a plan to force Batman to choose whom to save.^[23] Batman and Gordon were lied to about the locations of the victims, resulting in Rachel's death and Dent's survival with severe burns. The Joker later escaped custody by detonating a bomb hidden inside one of his men. It was revealed that corrupt officers, including detectives Michael Wuertz and Anna Ramirez,^[24] had been working with the Joker and were involved in the abduction of Dent and Rachel, which ultimately led to Dent's disfigurement. Gordon realized that the Joker had orchestrated his own capture in order to rescue Lau from custody and further destabilize Gotham City.

The Joker subsequently took control of the mob's resources, murdered the Chechen, and burned the mob's money, stating that he was motivated not by wealth, but by chaos. He also killed Lau—whom he had previously helped free—burning him along with the mob's fortune.^[25] He later issued a televised threat targeting Wayne Enterprises employee Coleman Reese.^[26] He warned that unless Reese was killed, he would destroy a hospital each day. This ultimatum caused widespread panic across Gotham.

At Gotham General Hospital, Dent suffered a psychological breakdown following Rachel's death. The Joker, disguised as a nurse, psychologically manipulated the embittered Dent into seeking vengeance against those he held responsible,^[27] including corrupt police officers, Batman, and Gordon. Declaring himself an "agent of chaos",^[28] the Joker espoused anarchy as the only fair system, encouraging Dent to abandon the rule of law and embrace chance.^[29] After placing a revolver in Dent's hand and reinforcing his belief in randomness and chaos, the Joker left Dent to determine his own course of action. Dent ultimately spared the Joker based on his coin toss.^[30][31] The Joker then detonated explosives to destroy the hospital and escaped amidst the evacuation, disguised as a nurse and commandeering a bus.^[32]

The Joker stated that he intended to rule the city and warned of a "surprise" awaiting evacuees at the bridges and tunnels, which had been rigged with explosives. Citizens instead fled by river using two ferries—one carrying civilians and the other prisoners.^[33] The Joker secretly planted explosives on both vessels and gave each group the detonator to the other, offering survival if one destroyed the other before midnight. Otherwise, he would destroy both.^[34] The scheme was intended to demonstrate the inherent corruption of society through a social experiment,^[35][36] testing whether ordinary people would abandon their morals.^[37]

Meanwhile, Batman located the Joker at the unfinished Prewitt Building and discovered that many of the apparent gunmen were actually hostages disguised as clowns, while the real criminals were dressed as captives.^[38] Forced to evade both the Joker's men and intervening SWAT teams, Batman subdued the criminals and rescued the hostages. He then confronted the Joker, who briefly gained the advantage by using his Rottweilers^[39] to attack Batman. As the deadline passed, however, neither ferry detonated the other, undermining the Joker's experiment.

Attempting to trigger the explosives himself, the Joker was stopped when Batman fired his arm-gauntlet blades at him and threw him off the skyscraper, but Batman used his grapple gun to save him from falling to his death.^[40] The Joker was then apprehended and arrested by the SWAT team, and subsequently incarcerated in Arkham Asylum.^[41]

Though he was arrested, the Joker left behind a destructive legacy; Gotham City was nearly torn apart by Harvey Dent's downfall and death. However, Batman prevented total ruin by taking the blame for Dent's crimes,^[42] allowing Commissioner Gordon to preserve the former district attorney's image as a "White Knight".^[43] This act eventually led to the establishment of the Dent Act eight years later, which restricted parole and saw dangerous criminals transferred to Blackgate Penitentiary, resulting in years of peace. Despite this, the mercenary Bane later exposed Dent's crimes, dismantling the act and plunging Gotham back into chaos, partially fulfilling the Joker's philosophy that individuals would abandon their moral code under pressure.