A young woman (Maika Monroe) pays for having some car-sex fun in a very, very big way in this creepy, ghoulish, unrelenting horror film from writer-director David Robert Mitchell. Taking more than a few cues from John Carpenter’s Halloween and the zombie works of George Romero, Mitchell is very much tuned into the sort of stuff that makes filmgoers squirm and sweat. The movie, based on one of his own nightmares, combines voyeuristic camera work, eerie soundtrack vibes and some fine acting for one of the better, old-school cinematic scares of the past decade. Monroe’s character gets cursed after having the aforementioned car sex. The curse involves an unstoppable force that can take the shape of any human, be it an old naked man on the roof or one of your parents. That force is not only out to kill the cursed individual; it’s out to kill the cursed individual in very violent ways. The shape-shifting “monster” proves a highly effective device, because you will find yourself constantly scanning every frame of this movie, evaluating every human being that appears. Crowd shots are especially unnerving. There are times when the “monster” is fairly apparent, and others where it is something vaguely visible in the back of the shot. In short, you don’t ever feel safe watching It Follows.