"Some men aren't looking for anything logical. They can't be bought, bullied, reasoned or negotiated with. Some men just want to watch the world burn." These are the words Michael Caine's loyal Alfred uses to describe the Joker, Batman's nemesis in "The Dark Knight." A follow-up to his 2005 origin story "Batman Begins," Christopher Nolan's "The Dark Knight" is a delightfully relentless thrill ride that forces Batman to face not only inner demons but those in the outside world as well. And, in a surprising twist and risky move (can we expect any less from the Nolans?), we find that Batman is not the star of the show; he has become the sidekick to a devilish villain.

In "Batman Begins," Bruce Wayne's childhood friend Rachel Dawes (then played by Katie Holmes) told him, "Justice is about harmony; revenge is about making yourself feel better." This realization gave birth to Gotham's hero, but the city now is far from harmonious. The mob manages to stay one step ahead of the police and even more criminals run loose in the city - even the Scarecrow (Cillian Murphy) makes an appearance. The "Bat-man" has even inspired copycat vigilantes, but they don't possess Wayne's means, technology, or style. The public has lost faith in the once-hailed hero, and Wayne (Christian Bale) wonders if the city no longer needs him. Along with Lt. Gordon (Gary Oldman), Wayne throws his support behind Gotham's new D.A. and white knight Harvey Dent (Aaron Eckhart), a determined do-gooder who has won the hearts of Gotham's citizens, including Dawes, with his public campaign to rid the city of the mob. Batman, however, realizes that his work is not finished when a psychopathic murderer known as the Joker appears. Claiming to be "a man without a plan," this madman organizes elaborate mind games and moral challenges to show Batman and his law-abiding comrades that even the best men are capable of falling into darkness.

What makes the Joker so horrifying is the lack of an origin story. Nolan does not waste time, for better or worse depending on your opinion, explaining what horrible event, science experiment gone wrong, or tortured childhood resulted in this scraggly-haired and scarred psycho in clown makeup. But then again, with the evil he displays on screen, what explanation would be enough? The Joker, throughout the film, offers several of his own anecdotes about his past and the origin of the scars that have left him perpetually smiling, but what is real and what is part of the game? 

Lucky for us, this most interesting character in the film is matched by a most-memorable performance by the late Heath Ledger. Will he be the first performer since 1971 to be awarded a posthumous Oscar? Ledger, who died of an accidental overdose early this year, poured every last drop of himself into this role to create this iconic character. Looking at the actor's unfortunately small body of work, it's a shame to think of what he might have become or accomplished later in his career. 

This final performance, however, is a perfect example of his ability to completely transform himself for a role. With a stilted walk that leaves his limbs dangling like those of a marionette puppet, Ledger's Joker first appears with only a hint of the madness to come. He is a sight to behold wearing cracked clown make-up and constantly licking his red lips - his tongue darts to the corners of his mouth in a creepily reptilian fashion. His voice, sometimes high-pitched and sometimes booming (Ledger incorporated influences ranging from classical actors to ventriloquist dummies), will haunt viewers long after the credits have rolled. Amazingly, he manages to portray the Joker with a creepy charm that repulses you but constantly draws you in and at the same time offer a bit of comic relief, even if the laughter dies in your throat. Coupled with Ledger's performance, the Joker's mission to reveal Batman's true identity to show Gotham that their "hero" is a fraud immediately forces all other of the film's plot lines into the background. 

Christian Bale, with chiseled features and a reluctance to smile, once again deftly handles the delicate balance of Bruce Wayne and alter ego Batman (or is it now the other way around?). Bale's performance is one of the key elements that gives Nolan's film a heftier emotional weight; Bale effortlessly erases all memories of previous, more cartoony Batman incarnations. "Batman Begins" gave viewers a much deeper look at what made Bruce the man he is today; those inner demons and tragic childhood are perhaps what draws him and the Joker together. They, as the Joker puts it, cannot exist without one another, if only to provide a constant reminder to Wayne of what might have happened had he chosen the path of revenge and destruction instead of justice and harmony. 

Maggie Gyllenhal provides a welcome change, albeit a not very imaginative one, to the character of Rachel Dawes. She is the weakest in the film, perhaps because she never really gets her hands dirty. Aaron Eckhart, however, is wonderfully charismatic as the slightly naive but ever hopeful Dent. His later transformation into Two-Face is quite ghastly, and though I'm not sure how the make-up or special effects were done to bring this realization to the screen, the result is nothing short of nightmarish.

The roles of Wayne's closest confidents, the technological genius Lucius Fox and the trusty butler/assistant Alfred have been reprised by Morgan Freeman and Michael Caine, respectively. Both men prove crucial to the action: in a move that smacks of current political commentary, Fox challenges Wayne on his use of Fox's designs to create an eavesdropping device to spy on all of Gotham. Alfred, the man closest to Wayne, protects him by making a decision about an important letter.

Whereas "Batman Begins" was more introspective and focused on Wayne's transformation into Batman, "The Dark Knight" is nonstop action. The images are crystal clear and scaled to impress as Nolan shot several scenes with the cumbersome but impressive IMAX camera. The final hour of the film is a relentless battle against the Joker, his chaotic and maniacal personality perfectly illustrated when he climbs out of an overturned 18-wheeler and stands in the streets, yelling "Hit me!" as Batman screams towards him on the Batpod. The Joker doesn't care whether he lives or dies; he just wants to show Batman that they have more in common than our hero might like to admit and that anyone can fall.

"The Dark Knight" is a rare and most welcome film in that it not only lives up to a year's worth of hype, but it also, along with its predecessor, lifts the comic book story of a caped crusader to high dramatic art. Featuring three-demensional characters that face ethical and moral challenges, "The Dark Knight" entertains but also touches on contemporary fears, worries, and politics to resonate with audiences. Exhilarating, horrifying, and mesmerizing, Nolan's takes on the Batman story have proven to be revolutionary to the comic book genre - gone are the days of simple good versus evil - and have become modern masterpieces. "The Dark Knight"'s 2 1/2-hour run time, packed with action that is also morally complex, leaves audiences in a rare state of being completely satisfied but ready for more.

In the end hangs the question of how Wayne and Batman will handle the vigilante's fall from favor in Gotham. He is, as he says, not a hero; he's whatever Gotham needs him to be. Robbed of the relationships that kept him human and hopeful for the days in which he is no longer needed, Batman will surely command a new and perhaps darker strength in exile. Will Batman himself be the villain in the next film? I'm sure that's something the Joker would love to see.