Ledger is truly scary, but the speed and volume of plot and action become overwhelming after two-and-a-half hours. The Joker apparently has some kind of super power no-one has yet thought of: he can rig ferries, hospitals or anything else to explode with the help of only about ten guys, which, because they all die during the crimes (as often as not by the Joker's own hand), are fully resupplied from the Endless Supply of Joker Henchmen Area. There's a lot of that. A vehicle chase seems to take about half an hour. So there's a lot of that. Then, sucking up more time and breaking the tone of the picture, there's an ethical crisis over cellphone monitoring which amounts to a pointless late-game distraction. And what's with the way Christian Bale talks when he's wearing the suit--even when everybody in the room knows who he is? It's the darkest superhero movie ever made, which is an achievement, but it seems, to get the darkness past the Hollywood suits, the creators had satisfy a determination to produce the highest-yet volume of sound and spectacular, convincing the viewer they've been entertained by pummeling them into accepting the fact. Keep your expectations reasonable, and let Ledger scare the bejeesus out of you.