Horror movies aren’t supposed to be particularly good. After all, the camp value in a slasher flick is often more of a draw than the thrills and chills. But in the last few years, horror has become an upmarket genre in Hollywood, with high-profile actors and actresses clamoring for a fright pic of their very own. Not only that, there’s been a demographic shift in the audience for horror: young women, traditionally used as cheap sexual props and helpless victims in the blood-‘n-gore fests of old, are an increasingly enthusiastic percentage of ticketbuyers.