Charlotte Sutton has made a career of catching out partners who are willing to cheat on their spouses. After giving up on ever finding true love, she has dedicated her profession to helping others determine if they are in a relationship with a keeper, or a liar. Business is booming and Charlotte is enjoying the reward of an uncomplicated life. That is, until the day comes that she is hired by Brooke to tempt the successful architect, Joseph Lawson, Brooke's very endearing fiancé. Suddenly, Charlotte's life becomes very complicated indeed. All she has to do is test his integrity. But what happens when her own morals are thrown into jeopardy, because she's falling for the man she's been hired to expose?