In "Gone Girl", there is a definite darkness to the marriage of Nick and Amy Dunne. When she disappears (or does she?), Nick is left as the primary suspect in the investigation and is caught in his lies and deceits. When he reveals that he's been cheating on Amy for a year with a young student of his readers may start to wonder if this was the reason for his wife's disappearence in the first place. The book alternates between his perspective and Amy's perspective and what it reveals is that a wife who has been cheated upon may use drastic measures to get revenge on her unfaithful husband. I loved how this was one of the major plot twists of the book and how she begins to dominate more of the book in the second half. She may certainly have some psychological issues but what she does to try to gain the sympathy of others is intriguing beyond doubt. "Gone Girl" is one of those books that you'll find difficult to put down and although it is slow-going at first once you get sucked in it is hard to pull yourself out of it.