If you like to watch plots unfold slowly as the movie progresses, like light bulbs going off revealing answers to perplexing questions as you go, I think you'll really like this movie. It shows the uniqueness of the bond between twins, as one twin gets "messages" or "visions" from the other as to why she's missing, and where she is. With their disturbing past being revealed as the story progresses, things get more and more unsettling. It's not the most "scary" movie I've ever seen, but it's got more intrigue and dark character building than a lot of horror films I've seen. The special effects are quality - it kept my attention all the way. And I think some of the characters were interesting that weren't necessarily the leads. My favorite part is the ending, which I really didn't see coming.