Bruce Wayne: I knew the mob wouldn't go down without a fight. But this is different. They crossed the line.
Alfred Pennyworth: You crossed the line first, sir. You hammered them. And in their desperation they turned to a man they didn't fully understand. Some men aren't looking for anything logical. They can't be bought, bullied, reasoned or negotiated with. Some men just want to watch the world burn.
The Joker: You wanna know how I got these scars? My father was a drinker and a fiend. And one night, he goes off crazier than usual. Mommy gets the kitchen knife to defend herself. He doesn't like that. Not...one...bit. So, me watching, he takes the knife to her, laughing while he does it. He turns to me and he says "Why so serious? He comes at me with the knife."Why so serious? Sticks the blade in my mouth...Let's put a smile on that face!