If you know the genre, you know the whole movie, but that's why it's so great. The movie is truthfull to genre and got it to near perfection. The cast is amazing, all characters are great and actor performances amazing. The mystery is great and so is the plot. Sadly the final plot twist was so overused, it is amazing if you see it for the first time, but I have seen it too many times and predicted it easily. On the good side after that the movie had the perfect ending shot like ever for this genre.