" People who work in slaughterhouses know that there is a spot on an animal’s forehead to be found by drawing an imaginary line from the right ear to the left eye and another from the left ear to the right eye. They aim the killing blow an inch or two above the junction of this X. My uncle taught me that. He didn’t work in a slaughterhouse, though. He just knew how to kill things. "

― Roger Zelazny , Trumps of Doom (The Chronicles of Amber #6)