Some choice quotes from the TIME review:
"There's a beautiful high-angle shot, early in The Dark Knight, that looks down on Bruce Wayne (Christian Bale) in full Batman regalia as he perches atop a Gotham skyscraper, surveying the city he lives to protect, then leaping off and spreading his majestic bat wings to swoop down into the night. Bruce's trajectory is also the film's. It traces a descent into moral anarchy, and each of its major characters will hit bottom. Some will never recover, broken by the touch of evil or by finding it, like a fatal infection, in themselves."
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"But Nolan has a more subversive agenda. He wants viewers to stick their hands down the rat hole of evil and see if they get bitten. With little humor to break the tension, The Dark Knight is beyond dark. It's as black and teeming and toxic as the mind of the Joker. Batman Begins, the 2005 film that launched Nolan's series, was a mere five-finger exercise. This is the full symphony."
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"This Joker is simply one of the most twisted and mesmerizing creeps in movie history."
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Actually, they're just diversions from the epochal face-off of Bruce and the Joker. For a good part of the film, when the two embrace in a free fall of souls one doomed, the other imperiled you may think you're in the grip of a mordant masterpiece. That feeling will pass, as the film spends too many of its final moments setting up the series' third installment. The chill will linger, though. The Dark Knight is bound to haunt you long after you've told yourself, Aah, it's only a comic-book movie.