Do Hyun Woo is a producer who has been working in television for over 10 years, and believes he is immensely lucky to have both a successful career and happy marriage. One day, he finds a reservation for a hotel room on his wife’s phone, which leads him to believe his significant other is about to have an affair. Because he isn’t sure how to solve this problem, he wants to reach out for advice but also does not want to compromise his privacy. So, instead of openly sharing his problem with the world, Do Hyun Woo decides to join the online forum, 'Cheated Spouses Anonymous'. There, he speaks to several members who have experienced the betrayal of a loved one, while attempting to heal his own insecurity. Adding to the his tensions are Do Hyun Woo’s old college classmate and his lawyer friend, with the straight-talking workaholic writer Kwon Bo Young rounding out the mess going on in Do Hyun Woo’s head. Will our Sherlock be able to solve this mystery of supposed infidelity, or will colluding with others that have been cheated on only intensify his paranoia?