The truth understood by every 14-year-old comic book fan is that we love superheroes not because they are “faster than a speeding bullet, more powerful than a locomotive, and able to leap tall buildings in a single bound,” but because these steel-bodied crusaders can beat the living daylights out of the most satanic boogeymen.

Campy or solemn, the Batman franchise has produced blockbusters for more than two decades because its creators knew that superheroes must vanquish villains—and the better the villain, the sweeter the victory. With the late Heath Ledger playing a criminally insane Joker who only wants Christian Bale’s Batman to come out and play carnage and slaughter in the streets of Gotham, the franchise has found a fiend fans will love to despise.

Still, the darker questions raised by these films are why we need such fiendish foes and what sorts of violence can be used to vanquish them. These are rarely the questions asked by adolescent audiences of summer blockbusters, but director/writer Christopher Nolan bumps up against them, prodding Batman and the film’s audience to wonder why we need to be superheroes (or superpowers), and to ask if there are any limits to the carnage we will wreak to vanquish our enemies.

Like the terrorist he is, Joker seems to grasp that his game is about unleashing the chaos of our fears and rage, about manipulating and seducing us into reactive mayhem. He has no plan except to make us crazy—and thus bloodthirsty. Can he move us to torture, to slaughter, to vengeance?

At times Nolan’s film is instructive regarding the dangers of splitting the world into friend and foe. At other times it slips into the same manipulative strategies of comic book melodramas, entertaining us by enraging us. Still, like Joker, this tale of a Dark Knight is a sobering reflection on our own temptations for superpower.