We knew almost nothing about this movie - and I strongly recommend that you do not watch trailers or talk to people about it - just go! Of course the movie starts slow - it's building the suspense. Allow yourself to be drawn into the lives of these two people. Watch as if it's real - and it feels Very Real. Without saying more, I will just say that I left the theater with weak knees and shaking hands. Terrifying!! Don't miss it - and don't wait to see it on DVD.