Probably not the most shocking ending but quite memorable and has totally stuck in my mind. It's the book, Whispers and Lies by Joy Fielding. You will have a hard time believing the ending of this novel. It kind of surprised me. It tells the story of a middle-aged nurse named Terry Painter who lives all by herself. She eventually allows Allison Simms, a much younger woman, to rent her place. The story then somersaults and becomes a murder mystery. Suspicions here and there. But that psychological twist is definitely my favorite. To those who may want to read this, I would not spoil the ending, don't worry. American Psycho is pretty good too, but a little bit obvious just by reading the title. How about you? What is the most shocking book ending you've ever read?