Mulder: He gunned him down just for spite. This is a man with a wife and two small children and you, you shot him without hesitation, without conscience, without an ounce of humanity. Which is why you should die like an animal, you son of a bitch!
Scully: What are you going to do?
Mulder: I know what I'm not going to do. I'm not going to hang around and wait for Barnett to send me another valentine.