It's no accident that the skyline of Gotham City figures prominently in so many scenes in The Dark Knight, the second Batman movie from director and co-writer Christopher Nolan. It's seen from above when Batman glides from building to building, and from below as the Joker skulks through streets that the residents deserted in panic. But it's just as conspicuously present in the film's many scenes of executives and city officials meeting high above the general populace, like gods determining the fates of those below. Where Batman Begins was largely about the considerable personal toll exacted by its hero's decision to fight back against the forces of evil while adhering to a code of honor, The Dark Knight expands those weighty themes to city scale.
As the film opens, Gotham still needs Batman (played again with intensity and vulnerability by Christian Bale), though its champion's influence hasn't been entirely positive. Organized crime has practically gone corporate in response, and a group of clumsy Batman wannabes have done little to stop it. Then there's the Joker, a mysterious new criminal who wants to foil the forces of law and order for reasons he keeps to himself.
What the Joker lacks in transparent motives he makes up for with enthusiasm. Playing a self-described "engine of chaos," the late Heath Ledger treats the iconic comic-book villain as a man who sees life as a dark joke, but takes care to tailor his punchlines for maximum impact. It's an unnervingly thorough performance, from the character's serpentine habit of licking his lips to the hitch Ledger throws into his stride that makes him like a wounded, angry animal. It's nightmare stuff with real-world roots, both in the randomness of his destructive acts of terror, and the imperfect systems designed to stand in his way.
Basing his schemes on the corruptibility of cops and criminals, Ledger's Joker homes in on the few who appear beyond his reach, particularly Batman and district attorney Harvey Dent (Aaron Eckhart), a fearless enforcer of the law poised to make real changes to the city. Matters are complicated by the fact that Eckhart now shares a bed with Bale's lifelong love Rachel Dawes (Maggie Gyllenhaal, subbing in for Katie Holmes). But to the film's credit, Nolan isn't afraid to keep matters complicated. The script, which he co-wrote with his brother Jonathan, has the unapologetic density of a good crime novel, with major and minor characters alike getting their due. Bale and Gyllenhaal have only a few scenes together, but they establish a tangible chemistry, and Michael Caine, Gary Oldman, and Morgan Freeman make significant contributions as Bale's confidantes and consciences.
Nolan lets the film's spectacular action scenes seem like the natural consequences of the conflicts between characters, conflicts that build until Gotham becomes less a setting than a stage for an operatic conflict between tortured good and contented chaos. As strong as The Dark Knight's setpieces are—and they're all pulsing showstoppers of a kind not seen in Batman Begins—the real tension comes from Nolan's willingness to let that battle's ultimate outcome remain in doubt even as the credits roll. The film's capes and cowls suggest one genre, but it's a metropolis-sized tragedy at heart.