The Dark Knight was released in 2008 as the follow-up to Nolan's "Batman Begins" in 2005. The Dark Knight is a character play primarily between Batman and The Joker. It delves deep into the Jungian Concept of Enantiodromia, the idea that the superabundance of a single force gives rise to its opposite - in this case Order and Chaos, Batman and the Joker. Most Americans are not familiar with such concepts and so the movie helped to introduce this dichotomy into the cultural vernacular coincidentally (or not?) right at a time when the stock market was on the verge of collapse immediately after the Dow Jones had peaked at its all time high, capping off the largest and most egregious credit expansion in history with its corresponding peak "boom" followed by immediate bust in the US and world economies. The film's premiere was also quickly followed by a sudden tragedy - the apparent suicide of the gifted actor Heath Ledger who played the Joker - the first, but unfortunately not the last, incident where the darkness of the film trilogy seemed to spill over into the real world (an unintended consequence). This film was exceptionally dark and yet highly cathartic. I myself was rather moved for days after viewing it - it seemed to have an effect on everyone.
The film opens with the scene of the Joker and some of his hired thugs robbing a bank. We are immediately given a taste of the Joker's potential to manipulate and deceive others, even in his own "circle", to do his bidding with absolutely no remorse and seemingly no thought given to any future consequences. During the opening robbery scene the Joker tricks each person involved in the robbery into shooting one of their accomplishes for purely personal gain until inevitably it is the Joker himself who makes the final hit keeping the profits for himself. While preparing to leave the scene of the crime on a school bus the bank manager tells him "You think you're smart huh? You're the guy that hired the goons. They'll just do the same to you. The criminals in this town used to believe in things - honor! respect! Look at you! What do you believe in huh?". The Joker then responds eloquently "I believe that which does not kill you makes you....stranger".
Later on in the film we are introduced to Harvey Dent, the young, energetic and deeply committed district attorney who is attempting to fight corruption in Gotham. Batman and Lieutenant Jim Gordon decide to include the sincere, new district attorney, who is dating Rachel Dawes, in their plan to tackle the mob and Bruce offers him a fundraiser. The new threat is not well received by mob bosses Sal Maroni, Gambol, and The Chechen who immediately convene a meeting to discuss how to deal with the matter as well as the increasing threat from Batman himself. During the meeting the mob cartels are are informed by Lau, a Chinese accountant, that he has hidden their funds and fled to Hong Kong to escape the new pressure. The meeting is then abruptly interrupted by the Joker who says
"Look, listen. I know why you choose to have your little group therapy sessions here in broad daylight. I know why you're afraid to go out at night; the Batman. You see, Batman has shown Gotham your true colors, unfortunately. Dent, he's just the beginning. And, and as for the television's so-called plan? Batman has no jurisdiction. He'll find him, and make him squeal. I know the squealers when I see them and...(points at Lau)"
They laughingly refuse when Joker offers to kill Batman for half the money and Gambol puts a bounty on him. Not long after, the Joker kills Gambol and takes control of his men. Later on Batman successfully kidnaps Lau from his office hideout in Hong Kong and brings him back to the US and hands him over to Gordon who holds him on charges of money laundering but only so he can question Lau to get more information on the mob. During this phase of the film we also get a heavy dose of Harvey Dent, Rachel's new soon-to-be husband who relentlessly pursues the mob even to the point that his own life is endangered. Rachel, Gordon and Bruce Wayne all fear for his life and worry that he will be targeted for having such a high profile as a district attorney and making so many public statements and appearances.
The Joker then issues an ultimatum that people will die each day unless Batman reveals his identity. Bruce briefly contemplates the possibility of revealing his identity but ultimately opts against it. When his demands are not met the Joker then orders a spree of hits against a high profile judge overseeing the mob trials and commissioner of the police (Loeb) which he executes perfectly to a t. The Joker then targets Dent at a fundraiser hosted by Wayne Enterprises but Bruce hides him, while Rachel is looked after by Alfred. This results in a final, all-out assault by the Joker where he attempts to assassinate the Mayor but (seemingly) kills Gordon instead. As a result Bruce plans to reveal his identity, but Dent instead names himself as Batman to protect the truth ("protecting" the truth is a common theme throughout the series).
At this point Dent is taken into protective custody and pursued by the Joker across the city as Batman rushes to aid. Gordon, who faked his death, helps apprehend the Joker and is promoted to Commissioner. However, Dent and Rachel are suddenly kidnapped. Batman begins interrogating the Joker. The exchange between them is visceral and memorable. The Joker tells Batman that he has no intention of killing him because "Why would I want to kill you? You complete me...".
http://www.youtube.com/watch?v=ohU16OiduUs
Batman interrogates the Joker further to get the location of Rachel and Dent but is told he has to chose which one to save - he chooses Rachel however later he discovers that the Joker has intentionally reversed their locations so he is forced into saving Dent instead. Dent is given one last conversation with Rachel courtesy of a speaker system arranged by the Joker that allows them to communicate with each other and he convinces her that everything will be OK. Batman finds Dent moments before the buildings explode, killing Rachel and scarring half of Dent's face with flammable gasoline - Dent goes into shock. The Joker then uses a bomb that he surgically implanted into a prisoner whom was recently taken into custody - an errant phone call from a police officer to a number given by the joker triggers the detonation device. Again, we are reminded of the Joker's seemingly limitless abilities to manipulate individuals into his bidding. He then escapes from the police department with Lau.
After the explosion and the death of Rachel, Dent is forever changed. His world of right and wrong, good vs. evil where he can crusade and be a hero has now been completely shattered courtesy of the Joker. Where before he saw destiny, now he sees only pain, suffering and most importantly, randomness.
Shortly thereafter, the Joker kills Lau and The Chechen, and threatens to bomb a hospital unless Reese (an Employee at Wayne Enterprises who threatens to rat out Batman on TV) is killed. The image of the Joker standing before a pile of burning money he just pillaged is particularly disturbing - he declares that Gotham deserves a new breed of criminal - one unmotivated by money or power but who commits crime purely for fun. This corresponds with something Alfred said to Bruce Wayne earlier in the film - "Some men aren't motivated by money. Some men just want to watch the world burn".
The Joker then pays a visit to Dent in the hospital dressed as a nurse and begins to manipulate Dent, who's face is now hideously disfigured on one side, into doing his bidding. Dent plays a game with the Joker where he tosses a coin and if the coin comes ups tails he kills him - The Joker passes this test seemingly unafraid of whatever consequence may befall him. The Joker then convinces Dent to take revenge on all the corrupt police officials who allowed the Joker to get access to information on Rachel and Harvey Dent's whereabouts and Dent (now officially "Two-Faced") goes on a killing spree using his burnt lucky coin to decide the fate of all those corrupt officials who were involved. Simultaneously the Joker blows up the hospital.
The Joker now begins to make threats against the entire city and many, in a state of panic, decide its time to flee Gotham. The Joker then rigs two ferries, one with citizens and the other with inmates from Arkham Asylum, with explosives as they attempt to flee the city. His voice then interrupts the intercom and he explains to them that they each have a choice - they can either be blown up themselves or blow up the other ship and save themselves. Fortunately both boats, including the one with the inmates decide not to go for the Joker's bluff (one of the inmates even tosses the detonator overboard). At this point Batman intercepts the Joker at his location where he had also tried kidnapping several police officers and forced them to impersonate members of his Clown Posse. Batman explains to the Joker "What were you expecting? Not everyone is as ugly as you! You're alone". Batman then rescues the hostages and, after being tempted to kill the Joker returns him to the Police where he is placed under arrest.
However the Joker has one final devastating trick up his sleeve - He explains that the citizens of Gotham will lose all hope once Dent's rampage goes public. Batman then leaves to find Dent. Dent lures Gordon to the building where Rachel died and holds his family hostage, as Batman confronts him. Dent judges the fates of Batman, himself, and Gordon's son with three coin flips. As a result, he shoots Batman in the abdomen, spares himself and flips to determine the boy's fate. Batman, who was wearing body armor, tackles Dent off the building before Dent can kill the boy, resulting in Dent's death. Batman convinces Gordon to hold him publicly responsible for the murders so that Dent will remain a symbol of hope for the city. A manhunt for Batman ensues, as he escapes on the Batpod. Alfred burns a letter written by Rachel to Bruce announcing her engagement to Dent....
A constant theme throughout the movie is that Batman and the Joker are enantiomers - mirror images that both give rise to the other. Bruce Wayne even discusses this dilemma with Alfred the Butler, explaining that his desire to fight crime and the creation of Batman, while initially successful eventually cornered the mob into doing something desperate - empowering the Joker who only terrorized Gotham even further which was an unintended consequence. He indicated that the criminals will just keep upping the ante to match whatever wizardry Batman can produce and seems to suggest that in the end perhaps there is no victory only eternal fighting. Carl Jung, the Great Psychotherapist and Student of Freud initially proposed the theory of Enantiodromia - the idea that an excess of any force will eventually produce its opposite. This is true for any situation where force (lethal or non-lethal) is being used by one group or individual against another - force gives rise to opposition and opposition gives rise to conflict. Thus the world forever remains in a state of conflict in spite of our best intentions and efforts.
The Character of Harvey Dent however is the most striking example of enantiomerism in the film. Dent essentially becomes his own enantiomer born of the trauma he suffered from having to live through his fiance' Rachel's death and his inability to come to terms with the fact that others sold them out and that the Joker planned it that way. He simply lost his way and no longer saw order and meaning in the world - only chaos. This was the Joker's intention all along - to show that Dent, Gotham's White Knight, could be turned and thus anyone could be turned - proving to everyone that society itself with its conventions and norms of "right" and "wrong" is essentially, a joke and thus chaos would reign supreme.
At the end of the film, Gordon and Batman decide it is best not to reveal the final fate of Harvey Dent and instead hold Batman responsible for the murders - essentially to "protect" the public from the truth. This is where the film wanders a bit into the realm of conspiracy theory. The idea of "protecting" the public from the truth has long been a theme among conspiratorial minded folks who believe that the "Powers That Be" (i.e. the State) gets to decide what narratives the society as a whole are subjected to - essentially what is "true" and "false" from a cultural perspective. I must admit I disagree with such principles and feel the truth is always the best medicine in the long run for the public as living a lie tends to produce psychotic behavior but perhaps I digress. The point is that the Director seems to be indicating that this phenomenon occurs often in our society and the public should be more weary of "official" narratives. At least I think that is what he is saying.
Lastly, the Joker, as played by Heath Ledger, represented a new kind of villain, one that was unmotivated by any conventional self-interest. His energy, in my opinion, seemed to reflect the underlying uncertainty and unpredictable nature of the economic crisis that was unfolding in the world in 2008 at the time of the release of the film - it was as though the director could sense such a large macro-event was about to occur. I would venture to say that the Nolan Batman Trilogy is the collective unconscious (another Jungian concept) in action - as darkness envelops our society from bad economics to chaotic weather to unending wars abroad combined with an underlying apathy in the public, the darkness from our subconscious is projected into film and cinema instead where we can dismiss it as pure fantasy even though part of us knows better.
For more on this final topic please read the following...
http://www.collapsenet.com/free-resources/collapsenet-public-access/item/8673-massacres-droughts-and-a-society-unraveling