It's often said that someone outside a marriage can never understand what goes on inside it. The relationship is defined by a million tiny nuances, habits and gestures that shape it. Whether a marriage works, or does not, cannot be explored by someone outside the relationship who is not privy to these moments between the couple.RANDOM HEARTS is the story of Vivien and Edward, two people who are thrust inside each other's lives --- and marriages --- because of their unfaithful spouses. They explore their marriages as a way to discover why their spouses cheated on them --- and when and how. Exploring the intimacy of these relationships has them looking at painful topics as they look not only at themselves, but also at what their marriages actually were beyond what they appeared to be. As they dig deeper into the stories, they also find themselves attracted to one another and the relationship between them grows.It is also the story of Lily and Orson, their spouses --- the other random hearts that came together and unraveled the marriages.The book opens with Lily and Orson dashing out of town for a four-day weekend together. They are at a juncture in the affair where decisions need to be made and they are looking forward to exploring them together. Disaster strikes as their plane crashes and their secrets are unraveled by a police detective. This same detective caught his wife in a dalliance with his best friend the year before and becomes preoccupied with the case. Readers see his need to understand his own story through Vivien and Edward. He delivers the news of their spouses' deaths with compassion, but also seems to be exploring their reactions to try to come to terms with his.Vivien and Edward look for the fractures in what they felt were solid relationships often painfully seeing their own failures, as well as those of their spouses. They ask each other probing questions that dig deep, but together they put together the story of what happened. The book is its strongest when it explores the inner marriages. We see how often Vivien and Edward were unhappy with elements of their partnerships, but never rocked the boat or carried a big opinion. Their roles seemingly worked within the framework of their relationship, but they now have learned to question who they were and how they impacted the marriages.The Sony movie Random Hearts is based on this book. Reading the book I kept visualizing Harrison Ford and Kristin Scott Thomas as Edward and Vivien. It had me juggling the story in a different way.One mistake I did note --- the flap copy refers to Vivien having a daughter when in fact she has a son. I think the one failure of the story is the way she walks away from her child as a symbol of something that is Orson's. I am not sure any mother as devoted to her child as Vivien would do that. But then again, the jolt and the jar of realizing that your entire world is not what it seems may also skew this part of the story to evolve like this.Written by Warren Adler, who also authored THE WAR OF THE ROSES, RANDOM HEARTS is a story of love --- and its mystery.