There are so many ways to find out. From a cell phone. From a bank statement. From some weird supermarket encounter. One morning in early January 2005, Wendy Plump's friend came to tell her that her husband was having an affair. It was not a shock. Actually, it explained a lot. But what Wendy was not prepared for was the revelation that her husband also had another child, living within a mile of their family home.

Monogamy is one of the most important of the many vows we make in our marriages. Yet it is a rare spouse who does not face some level of temptation in their married life. The discovery of her husband's affair followed betrayals of Wendy's own, earlier in the marriage. The revelations of those infidelities had tested their relationship, but for Wendy, it was commitment-the sticking with it-that mattered most, and when her sons were born, she knew family had to come first. But with another woman and another family in the picture, she lost all sense of certainty.

In Vow, Wendy Plump boldly walks one relationship's fault lines, exploring infidelity from the perspective of both betrayer and betrayed. Moving fluidly from the intimate to the near-universal, she considers the patterns of adultery, the ebb and flow of passion, the undeniable allure of the illicit, the lovers and the lies. Frank, intelligent and important, Vow will forever alter your understanding of fidelity, and the meaning of the promises we make to those we love.