I had previously read Maine by Sullivan and was mildly impressed by it. When I heard about this book, it sounded like a lot more interesting of a plot line and it did not let me down. The story spans over fifty years, from the beginnings of the tagline "A Diamond Is Forever," to the application to pro-marriage, anti-marriage, affairing, struggling couples. There are four couples featured throughout the book, plus Frances Gerety, who came up with the line. One couple has been married for thirty years and find out that their son has left his wife for another woman. A second couple lives in Europe and she leaves her husband for her lover. The third couple struggles to make ends meet, but love each other dearly. And the final couple doesn't believe in marriage. The story revolves around how diamonds are the connecting thread through all of the couples.