This thriller is quite well executed. Things remain quite plausible and don't descend into silliness so the movie is more effective. The psycho in question has a good reason to exact her punishment on the woman who had an affair with her Father and cause the destruction of her family. She cleverly worms her way into the family of the mistress and subtly wreaks havoc on their lives. Likeable cast all round.
Worth a watch.
Worth a watch.