The Dark Knight was filmed primarily in Chicago, as well as in several other locations in the United States, the United Kingdom, and Hong Kong. The director has used an IMAX camera to film four major action sequences, including the Joker's first appearance in the film. The Bat-suit has been redesigned, with a cowl allowing Bale to move his head. The film also introduces a recreation of the Bat-cycle, known as the Bat-pod.

Plot
The Dark Knight opens with Batman, Lieutenant James Gordon, and new district attorney Harvey Dent beginning to succeed in rounding up the criminals that plague Gotham City. They are unexpectedly challenged when a mysterious criminal mastermind known as the Joker, appears in Gotham. Batman's struggle against the Joker becomes deeply personal, forcing him to "confront everything he believes" and to improve his technology to stop the madman's campaign of destruction.

Cast and Characters
Christian Bale as Bruce Wayne / Batman: A billionaire who has dedicated himself to protecting Gotham City from the criminal underworld. He has got trained in the Keysi Fighting Method (KFM), and performed many of his own stunts. He did not gain as much muscle this time, because of the storyline in which Batman builds a new suit that allows him to move with more agility.

Heath Ledger as The Joker: Heath Ledger described the Joker as a "psychopathic, mass murdering, schizophrenic clown with zero empathy". To prepare for the role, Ledger lived alone in a hotel room for a month, formulating the character's posture, voice and psychology. He started a diary, in which he wrote the Joker's thoughts and feelings to guide himself during his performance. After shooting of the film concluded, Ledger died on January 22, 2008 at the age of 28, due to an accidental overdose of prescription medication, leading to intense press attention and memorial tributes. Nolan has dedicated the film to Ledger's memory.

Aaron Eckhart as Harvey Dent / Two-Face : The Gotham district attorney; Dent's battle with the Joker turns Dent into a murderous, disfigured vigilante called "Two-Face". Wayne sees Dent as his heir, which comes back to the theme of him realizing that being Batman will be a lifelong mission, and the tragedy that follows when Dent is corrupted.

Maggie Gyllenhaal as Rachel Dawes : The Gotham assistant D.A. and childhood friend of Bruce Wayne, she is one of the few people who know that he is Batman.

Michael Caine as Alfred Pennyworth : Bruce Wayne's trusted butler and father figure who tend tended to Wayne Manor.

Gary Oldman as Lieutenant James Gordon : One of the few members of the City of Gotham Police Department (GPD) who isn't corrupt. His tenuous, unofficial alliance with Batman and Dent is put in jeopardy when the latter becomes Two-Face.

Morgan Freeman as Lucius Fox : The recently-promoted CEO of Wayne Enterprises who supplies Bruce Wayne with the gear necessary to carry out Batman's mission.

Box Office Performance of Batman Series of Films

• It is the first film to be released in the Batman series during the month of July whereas all previous films were released in June.
• It the first live-action Batman film without the word "Batman" in its title.
• Friendly rivalry between Bruce Wayne and Harvey Dent is the "backbone" of the film.
• The movie was shot in Chicago, Baltimore and several other parts of USA, London and Hong Kong.
• For its release in IMAX theaters, movie’s four major action sequences were shot in that format, including the Joker's introduction.
• Bat suit was constructed from 200 individual pieces of rubber, fiberglass, metallic mesh, and nylon.