“Batman: You don't understand. I don't think you've ever understood.
Jason Todd: What? That your moral code just won't allow for that? It's too hard to cross that line?
Batman: No! God Almighty, no. It'd be too damned easy............But if I do that, if I allow myself to go down into that place... I'll never come back.
Jason Todd: Why? I'm not talking about killing Penguin or Scarecrow or Dent. I'm talking about *him*, just him. And doing it because... because he took me away from you.
Batman: I can't. I'm sorry.”
―
Judd Winick,
Batman: Under the Red Hood