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Well, when you're dealing with Halloween or any kind of horror movie like that, you're dealing in very familiar territory. You have Psycho as kind of the granddaddy of that kind of movie. Not that it's the greatest ever made, but it's the one that influenced everyone. That principle of the suspense, the Hitchcock suspense thing, of showing the bomb and you can get much more suspense than surprise is true, but what you can do is: once you establish the suspense, then you can do your shocks along the way, and that'll scare the hell out of people. They'll go completely crazy. They know something's gonna happen. In a horror movie, you go and you know something is gonna happen. The question is when?

John Carpenter
from a video interview (watch here)