Because he's the hero Gotham deserves, but not the one it needs right now...and so we'll hunt him, because he can take it. Because he's not a hero. He's a silent guardian, a watchful protector...a dark knight.
Batman: I see without seeing. To me, darkness is as clear as daylight. What am I? The Riddler: Please! You're as blind as a bat! Batman: Exactly. [throws a batarang at his throne]
