I haven't been straight-up petrified watching a film in a long time. Excellent acting, very compelling. Slow but steady build and just when you think it's going one direction, the pace switches up and it's ON. Loved it. My only complaint would be to make sure you turn on closed captioning because I couldn't hear what the characters were saying in most of the early part of the film. I will add that I've noticed in the reviews that this movie hits home more with female viewers than with males, possibly because more of us have had to deal with creepy situations and wondered what may have happened if we hadn't gotten lucky and dodged the weirdo. I do agree that it would have made a ton more sense if he'd put a tracker on her without her knowing it because he seemed to constantly track her down. But I'm guessing something got edited out that shouldn't have, maybe.