The pop-culture appetite for Batman seems inexhaustible; thousands of comic books, several movies, endless animated iterations, some of which are quite good and some of which are rather bad. Is there any real need to return to the character beyond the profit motive, though? After the financial and critical success of Batman Begins, the powers-that-be behind The Dark Knight could have made a safe bet of a sequel; a little more action, a few more actors, more of the same and a few extra explosions.

What's telling about The Dark Knight, though, is how risky it is -- how it's bold and brave and truly exciting, full of rich and strong performances and some real ideas along the way. Why return to Batman? It turns out that for Christopher Nolan, the reason to come back is that there's something to say about, and with, the character even after decades of stories and multiple reinventions. I was hoping The Dark Knight would be good; I had no idea that director and co-writer Christopher Nolan was going to make a film that not only addressed the philosophical and political conflict between the rule of force and the rule of law but also takes on the timeless clash between order and chaos ... and, along the way, evokes everything from Michael Mann's Heat to John Ford's The Man Who Shot Liberty Valance. ...

We're plunged into the thick of things in The Dark Knight, opening with a bank robbery that's brazen and bloody and brilliantly executed; we meet the mastermind behind it, The Joker, played by the late Heath Ledger as a preening sociopath with a super-heated brain and ice water in his veins. Not only is Ledger's performance worthy of Oscar consideration (although I think another actor does equally strong but less showy supporting work in the film), but it also instantly and thankfully erases any lingering memories of Tim Burton's wrong-headed decision to cast Jack Nicholson as the character in 1989's Batman. Nicholson's casting was designed to shock and awe, but the millisecond of amazement the audience felt at the sight of one of our greatest actors decked out in clown makeup and fake scars came at the expense of any real action; Nicholson's Joker gave the impression that the greatest physical task he might be capable of was stooping to pick up his paycheck. Ledger, though, is an entirely different case; whipcord-gaunt, pale and smeared as a dead man walking, oozing physical threats and, more importantly, twitching with the will to execute them.

The Joker's crime spree comes precisely as two of Gotham's most stalwart defenders are fighting the good fight to clean up their beleaguered city: As district attorney Harvey Dent (Aaron Eckhart) leads the public and legal effort to clean up Gotham, Batman (Christian Bale), the costumed identity of billionaire Bruce Wayne, attacks crime from the darkness; police lieutenant James Gordon (Gary Oldman) works with both parties in their efforts, just as assistant D.A. Rachel Dawes (Maggie Gyllenhaal, replacing Katie Holmes) is dating Harvey after her past with Bruce. Bruised and battered, Wayne knows his one-man vigilante secret war can't, and shouldn't, be sustained; he's just hoping to get Gotham on its feet enough so that Dent's legal and public efforts can take root. And, like that, co-screenwriters Christopher and Jonathan Nolan (working from a story by Christopher Nolan and David S. Goyer) invest Batman's character with more complexity than we've had in any previous big-screen incarnation of the comic-book icon: Batman's a warrior fighting to make himself obsolete.

Fortunately for us, the philosophical struggles aren't the only battles in The Dark Knight; Nolan fills the movie with visceral action, aided by both the cinematography of Wally Pfister, capturing the bruise-blue nights and concrete-canyon daytime of a fictional metropolis that feels epic yet real, and the tones and themes in the moody, soaring score by James Newton Howard and Hans Zimmer. Even in the midst of all this craft, though, the actors make the film's struggles and battles come alive. Eckhart may not have as flashy a role as Ledger, but he's just as impressive -- showing us a good and decent man and yet giving us small hints at the flaws beneath the veneer of respectability, cracks that can be used to bring everything down. ... As for Christian Bale, while his growl as Batman is disconcertingly close to comedic, his work here as Bruce Wayne is impressive, finding the flesh and marrow and full dimensionality of a character born out of ink-and-color flatness. Bruce Wayne's masquerade as Batman (or, as The Dark Knight continues thematically from Batman Begins, vice-versa) requires him to fool everyone; what makes Bale's performance more than just heroic posturing is a superbly executed moment of real drama where we witness how Bruce Wayne's capable of fooling himself.

Some will suggest that The Dark Knight's two-and-a-half-hour running time is on the unwieldy side; I most definitely found that not to be the case. The Dark Knight never flags or falters, even as it casually drops in a subplot about Batman taking the liberty of Gotham's residents so as to provide them with security without their knowledge or consent, or sets the starting ground for a new and intriguing direction for a possible third film to explore. (The endgame in The Dark Knight may be lengthy, but considering how perfunctory the finale of Batman Begins felt, it's definitely an improvement.) Comic-book movies are often bland and big meditations on good versus evil; The Dark Knight gives us a more interesting examination of right versus wrong, and how little it can take to shove the one into the other.

After critic David Denby savaged one of his Batman films, noted hack Joel Schumacher defended the idiotic excess of Batman and Robin and Batman Forever by asking "Well, it's based on a comic book; what did he expect, Long Day's Journey into Gotham?" What Shumacher did not understand -- and that Nolan, thankfully, does -- is that while any Batman film is by definition based on a comic book, that film can still have actual drama, actual characters, and something to say beyond Biff! Bam! Pow! action and simplistic camp. The Dark Knight may be based on a comic book, but it's a real movie made by real talents -- exciting, engaging, gorgeously crafted and thematically rich. Nolan's set himself up for a third film, of course, and even with Ledger's passing removing the possibility of his returning to the series, there are still plenty of places Nolan might take Batman; the confidence, vision and skill he's brought to The Dark Knight make that something to be hoped for.