When a wife becomes the breadwinner of her family after her husband loses his job, adultery becomes part of her life.
Choi Bora (Jeon Do-yeon), who works at an English language institute, is having an affair with her ex-lover, Kim Il-beom (Ju Jin-mo). Her husband, Seo Min-ki (Choi Min-sik), is a former banker. He has lost his job, and has taken over the domestic roles of the house: cooking, cleaning, and watching the baby. In his free time, he watches soap operas and reads romance novels. Min-ki is aware of the affair, but seems willing to put up with it and to continue living with his cheating wife. Bora is disturbed when Il-beom seems to want to take their affair further and pushes past her boundaries, risking to expose their relationship.
Choi Bora (Jeon Do-yeon), who works at an English language institute, is having an affair with her ex-lover, Kim Il-beom (Ju Jin-mo). Her husband, Seo Min-ki (Choi Min-sik), is a former banker. He has lost his job, and has taken over the domestic roles of the house: cooking, cleaning, and watching the baby. In his free time, he watches soap operas and reads romance novels.
Min-ki is aware of the affair, but seems willing to put up with it and to continue living with his cheating wife. He loves their infant daughter dearly. He tells Bora he intends to start a new business and try to get back on his feet. In that same conversation, he also tells her that he would be happy if she was a good mother for their baby. This is incompatible with her affair. Bora is disturbed when her lover appears to want to take the affair further and push past her boundaries, risking to expose their relationship. Il-beom calls her at home and even shows up at her door. Bora ends up drugging her own child, and Min-ki finds the toddler alone at home, and brings her to the hospital.
The movie then spirals towards its conclusion, with Min-ki apparently leaving by train, accompanied by his female friend, who lives in the same building. However, in reality he comes back to the apartment, kills Bora and frames Il-beom. The neighbor finds Bora's body, and In light of Il-beom's suspicious behavior, plus the planted evidence, the police seems convinced that the latter is responsible for Bora's death.
