Wrong vs. right, the individual vs. society, id vs. superego, action vs. reason, the Joker vs. Batman. There's a two-faced pleasure to be had in watching "The Dark Knight." Our rebellious impulses are excited by seeing an agent of chaos gleefully trample our societal norms, and our consciences are appeased by the cocky criminal's defeat.

The new chapter in the Batman saga expresses that tension in operatic style, with extravagant action counterbalancing the dramatic heft of a "Godfather II." Writer/producer/director Christopher Nolan and his collaborators have delivered an elegant, urgent epic that doesn't just extend the franchise, but deepens it into a film noir morality tale. Even as it upholds ideals of law and order it shrewdly questions the queasy morality of vigilantism, the mob mentality of a society facing terrorist anarchy, and the fine line between idealism and madness.

Nolan's achievement in the Batman films is to place the costumed superhero in a setting of real-world plausibility, encouraging us to suspend our disbelief. Notice that the Caped Crusader is rarely glimpsed for long or in full light. He haunts the film as a presence, since seeing him completely would make him appear incongruous.

With atmospheric Chicago locations representing Gotham City, military-design Bat-vehicles and an ensemble of topnotch character actors, the films have a believable, hyper-real texture. The film's visual strategy is so assured that we get a sure feel for this time and this place.

Gotham is making strides against its criminal underworld, and Bruce Wayne (Christian Bale) anticipates hanging up his cape as crusading District Attorney Harvey Dent (Aaron Eckhart) breaks up the mobs in court. Wayne doesn't realize that Dent has also won over his beloved Rachel Dawes (a luminous Maggie Gyllenhaal stepping into the role originated by Katie Holmes).

But just as Batman tackles high-profile crooks, a new figure of evil arrives to challenge the city's masked defender. A homicidal psycho with a clown mask of smeared greasepaint covering horrific scars tells a meeting of Gotham's criminal factions that the answer to their problems is simple: Kill civilians until the Batman reveals his identity, then kill him.

As the Joker, Heath Ledger gives a performance that is some kind of bizarre masterpiece. It isn't a smart-aleck act like Jack Nicholson's. Ledger inhabits the character's madness seamlessly, taking the role as seriously as Hamlet, another homicidal nut job. The Joker is well positioned to succeed in eliminating Batman where mere mobsters have failed, because he operates outside the logic of criminality.

A bravura bank-heist sequence that opens the film establishes that at his level of amorality, the concept of honor among thieves is a joke. Grotesque, sadistic and irrational, he doesn't want money, doesn't fear pain or capture. He doesn't even hate his nemesis: Speaking in a whining, insinuating drawl, he tells Batman, "You complete me."

The Joker simply delights in chaos, and bringing down Batman and hot-dog D.A. Dent is the most amusing path to his goal. With some guns and a few barrels of gasoline, he pushes Gotham to the edge of panic, turns the citizens against their onetime hero and makes a good man face the evil in his spirit. There's a hint of existential poetry in Dent's line, "You either die a hero or you live long enough to see yourself become the villain."

The film is bracingly ambitious, from the weightiness of its themes to the bold decision to kill off a major character. But Nolan hasn't simply made a popcorn movie for brainiacs. He's an increasingly self-assured director of action sequences. There are car chases here that belong on the short list of the best ever filmed, and apocalyptic stunts involving semitrailers, helicopters and exploding buildings. It's not a gratuitous piling-on of special effects; Nolan and his cinematographer Wally Pfister echo the kinetic energy of comic books in each slam-bang scene. If possible, plan to see the film in an Imax theater; six sequences were shot with the large-format cameras and they add a spectacular visual punch.

It's been a long time since we've seen such a wealth of imagination and energy onscreen, or a pop blockbuster so well acted and carefully thought out. "The Dark Knight" is the brightest light of summer so far.

Colin Covert • 612-673-7186