When John Carpenter and Debra Hill began to sketch out their ideas for Halloween, they dreamed up a list of scares. The creepiest images, the most unsettling scenes they could imagine. A clown with a knife. A gravestone in a bedroom. A pale face emerging slowly from the shadows. A person pinned to a wall by a blade. Or—how about this one?—a woman gets into a car and finds the windshield fogged up. The wipers kick on with no effect.