A group of criminals in clown masks break into a large bank where the mafia keeps its money. In the midst of the robbery, the five men in clown masks discuss whether or not to give their sixth member, someone called "Joker," a cut of what they robbed. They talk about how the Joker wears makeup—"war paint"—in order to scare people. As the robbery continues the clowns begin killing each other in order to get a larger cut. They shoot the bank manager in the midst of it all, after he tries to go after them with a shotgun.
There are only two clowns left, when suddenly, a giant school bus comes crashing through the wall of the bank, killing one of them. A clown emerges from the bus, and the remaining clown shoots him after they load up the school bus. The bank manager is lying on the floor, whimpering, and tells the remaining clown that "criminals in this town used to believe in things: honor, respect."
The clown puts a grenade in the manager's mouth, and the grenade's pin is attached to a cord, which is attached to the bus. As he boards the bus, this clown takes off his mask to reveal that he is The Joker. The Joker gets on the bus and drives away, pulling the pin and revealing that the grenade is a gas grenade. As the police arrive, the Joker has already left, driving the school bus filled with cash.
We hear the mayor being interviewed on television about cleaning up the city. A news interviewer asks the mayor about Batman, a superhero who has been helping to scare away criminals. We then see two detectives—James Gordon and Anna Ramirez—discussing the unknown identity of Batman. Gordon asks Ramirez about her mother, who is in the hospital, and she asks him if Batman will be showing up that evening.
A group of Russian mobsters, led by the Chechen, arrive in a parking garage to discuss a drug sale with the Scarecrow, another Gotham criminal who recently got out of Arkham Asylum. The drug they are discussing has the effect of making the user afraid. As they discuss it, they are interrupted by a group of citizens with guns, all dressed as Batman. The Scarecrow disseminates the fear-inducing drug on the Batman imitators.
The Batmobile, Batman's vehicle, arrives on the scene, which scares away the mobsters after initiating some explosions. Batman emerges and knocks out one of the Batman imitators with their gun. When the Chechen unleashes some of his rottweilers on Batman, they bite his arm and he takes them out. As the Scarecrow tries to escape in his van, Batman cuts it with his weapon known as the mangler, but the Scarecrow gets away. Batman manages to halt the van and tie up the Scarecrow as well as some of the mobsters for the police. A Batman imitator tells Batman he wants to help, but Batman insists he doesn't need any. "What's the difference between you and me?" asks the imitator, and Batman responds, "I'm not wearing hockey pads."
Ramirez and Gordon go to the bank that has been robbed and observe security footage of the Joker. "What's he hiding under that makeup?" Gordon says. When Batman shows up, Gordon shows him the picture of the Joker and they discuss the fact that the money has been irradiated in order to make it easier to trace. Batman suggests that they ought to focus on the mob rather than worrying about the Joker. Gordon mentions the new DA, and Batman asks if he trusts him. "I hear he's as stubborn as you are," replies Gordon.
The next day, a butler named Alfred visits Bruce Wayne at a secret location. Bruce is stitching himself up from the dog bites he suffered the previous evening. Bruce tells Alfred that his armor is too heavy and that he is carrying too much weight, and that he is disheartened by all the copycats who showed up with guns the previous evening. Alfred makes a reference to the new DA, and Bruce gestures towards cameras on which he is monitoring the DA. Alfred points out that the DA is dating a young woman named Rachel Dawes, someone Bruce appears to have fond feelings towards. "Who Rachel spends her time with is her business," says Bruce, dismissively.
We see Rachel in court sitting beside Harvey Dent, the new DA. Harvey flips a lucky coin to see who will lead in court. They are prosecuting a mobster named Salvatore Maroni, the mobster people believe is the new leader of the Falcone family. In the middle of the court case, one of Maroni's men, who is unexpectedly taking the fall for the mob boss, pulls out a gun and shoots it at Harvey, but it doesn't go off. After the fall guy is brought away, Maroni is later set free, much to Harvey and Rachel's despair.
As they leave the courtroom, Rachel comments on the fact that the mobsters trying to kill him must mean that they are getting to them. Harvey tells Rachel that he's meeting with Gordon and she asks him to "try to be nice."
Harvey goes to a meeting with Gordon and tells him wants to know more about Batman and to meet him. The two men argue and Harvey tells Gordon he doesn't like that he has his own special unit "full of cops I investigated at Internal Affairs." Gordon then asks Harvey for warrants to search some banks that are holding the remainder of the mob's money, and Harvey agrees in exchange for Gordon's trust. "You don't have to sell me, Dent. We all know you're Gotham's white knight," says Gordon. Harvey refers to a former nickname of Gordon's that Gordon alleges not to know about.
The scene shifts to a board meeting at Wayne Enterprises. Lucius Fox is heading the meeting, in which they are discussing teaming up with Lau Security Investments in Hong Kong. When he motions to Bruce, Bruce is asleep. After the meeting, one of Lucius' assistants tells him, "I know Mr. Wayne is curious about how his trust fund gets replenished, but frankly, this is embarrassing." Lucius tells him to let him worry about Bruce and goes into the board room, where Bruce tells Lucius that they ought not to go into business with Lau because it would be illegal based on Lau's profits. He then tells Fox he needs a lighter suit, so that he can be faster and more flexible, and Lucius agrees.
Harvey and Rachel go out for dinner and Harvey tells her it took him three weeks to get a reservation. Bruce walks up and greets Rachel, introducing her to his date, Natasha, the prima ballerina for the Moscow Ballet. Bruce introduces himself to Harvey and insists that they all have dinner together. Over drinks, Natasha says she would never want to raise children in a city like Gotham, "a city that idolizes a masked vigilante." When Harvey stands up for Batman, saying that he is a necessary figure in the city, Bruce warms to the new DA and tells him he wants to throw a fundraiser on his behalf.
The mobsters meet in a restaurant kitchen, where Lau appears to them on a television and tells them that their money has been moved to a secure and secret location, while Gordon searches the banks. The Chechen speaks up and expresses his worry about the Joker, who stole $68 million, but Maroni suggests that the Joker does not matter.
Suddenly, the Joker comes into the room and offers to do a magic trick. He sticks a pencil into the table and slams a hostile mobster's head into it, saying that he made it "disappear." The mobsters call The Joker a freak, but he sits down at the table and attempts to level with them. He warns them that the mob is losing power because of Batman and Dent, and tells them that Lau is a "squealer," before suggesting that they have to kill Batman. When Maroni asks why the Joker hasn't killed him already, Joker tells him, "If you're good at something, never do it for free." The Joker then asks for half of the money.
When one of the mobsters, Gambol, becomes impatient with the Joker, he opens his jacket to reveal a bunch of bombs, which startles the criminals assembled. Gambol says he's going to put a price on the Joker's head, and the Joker leaves his card, before shuffling out of the kitchen.
Harvey meets Batman on a roof. When Gordon comes up, Harvey tells him that Lau is on his way to Hong Kong. Harvey and Gordon fight about the fact that they are each foiling one another's plans, and Harvey asks Batman to bring Lau back to Gotham.
Bruce meets with Lucius and tells him he needs to travel to meet with Lau. Lucius shows him his new suit and they plan to go to Hong Kong together, where Lucius will help make it look like Bruce is simply traveling there to cancel negotiations with Lau's company. Bruce and Alfred then prepare a private and secret flight to Hong Kong. As Rachel and Harvey arrive at the ballet, they see a newspaper article posted that states that Bruce Wayne fled the country with the entire Moscow Ballet, a trip that Alfred has arranged as an alibi for Bruce. We then see Bruce on a yacht sipping a cocktail, as a plane arrives to take him to Hong Kong.
The first scene of the film is dark and unsettling, setting the scene for the crime-addled world of Gotham City. We see a number of bank robbers in grotesque clown masks robbing a large bank and knocking each other off as they do so. The world of the film is lawless on many levels, with criminals hurting one another and looking out only for themselves; this extreme lawlessness is satirically addressed by the wounded bank manager, who cries out, "Criminals in this town used to believe in things: honor, respect." In the world of The Dark Knight, criminals kill one another and innocent people without pause and crime is a pervasive state of existence.
At the center of this crime ring is the particularly lawless, unpredictable and deranged villain, the Joker. We hear about him before we see him, as the bank robbers discuss his off-putting habit of wearing clown makeup in his daily life as a kind of war paint to scare people. This detail shows us that the Joker's transgression is not only defined by his penchant for actual criminality, but by his transgressive identity as a social outcast more broadly. Not only does he expertly commit crimes, but he is never out of character; when he pulls off his clown mask, he is still wearing the frightful clown makeup that constitutes his identity as "The Joker."
Like the Joker, Batman is also never publicly out of character, and equally mysterious. No one knows the true identity of Batman, as he is especially quick, capable, and elusive. The only thing most people know about Batman is his uniform, inspired by a bat, and the fact that he never uses guns. When one of the Batman imitators asks him what the difference between them is, Batman simply says, "I'm not wearing hockey pads."
Batman is defined by his isolation and his rejection of the help of others. As a vigilante crime fighter, he is careful to protect his identity and ensure that he is the only one fighting the crimes that he fights. Efficient, cranky, and sporting a performatively gruff voice, Batman bears much in common with a lone ranger or a hardboiled detective from a traditional film noir. He does not want the help of others and wants only to hunt down criminals in the most effective and systematic way. He is not showy in his performance as a crime-fighter, opting for force and precision in favor of flamboyance.
In this way, Batman and the Joker are foils for one another, polar opposites in how they approach their respective projects. Batman is agile, logical, forceful, and steady, where the Joker is showy, unpredictable, irrational, and squirrelly in his methods. Bruce Wayne is a billionaire with high-tech gadgets and a glamorous lifestyle, a James Bond in a black, form-fitting suit. Contrastingly, the Joker is a mangy clown, covered in clumping makeup, ruined by trauma, and fond of mind-bending-ly incalculable movements such as lining the inside of his coat with bombs. Where Batman is a cool-headed keeper of the peace, the Joker is a bewildering trickster.