My review of The Other Sister can be summed up in one word: ingenious.The story was original with a truly unique plot line. Every time I guessed the killer there would be a red herring to change my mind. As the story progressed the investigations turned in a way I was not expecting. I was enjoying this story but the revelation took it into a darker area, I was hooked.The Other Sister blew me away, I recommend this book to all fans of psychological thrillers.