Ji-Sook is sent to South Korea to take her husband Tae-Soo back o North korea. Tae-Soo is an agent of the South Korea National Intelligence Service. 15 years ago, Tae-Soo infiltrated North Korea, marred Ji-Sook and had a son. He then returned to South Korea, leaving behind Ji-Sook and their son. Ji-Sook and her son were then sent to a forced labor camp due to her husband's actions. High-ranking North Korean officials trained Ji-Sook and sent her to South Korea to carry out a mission. Her mission is to persuade Tae-Soo to go back to North Korea. Ji-Sook's son is held as a hostage.

Meanwhile, Sung-Ho is a detective, who has a son. He lost his wife 10 years ago. One day, Sung-Ho and his son eat at a small neighborhood restaurant they often frequent. Sung-Ho and his son talk about who will do household chores and the restaurant owner suggests someone that can do the chores. At first, Sung-Ho says no, but then he sees Ji-Sook walk into the restaurant. Sung-Ho falls in love with her at first sight. Sung-Ho asks the restaurant owner if Ji-Sook is the woman who can do the household chores. The restaurant owner replies yes. Sung-Ho decides to hire Ji-Sook at that moment. Sung-Ho has no idea that Ji-Sook and the restaurant owner are North Korean spies and they approached him on purpose.

인질로 수용소에 갇힌 어린 아들을 위해 전 남편에게 총을 겨눠야 하는 여성 북한공작원이 있다. 그리고 아무 것도 모른 채 그녀와의 장밋빛 미래를 꿈꾸며 신이 난, 아들 하나와 사는 철없는 홀아비 형사가 있다. 둘의 만남을 통해 체제와 이념을 넘어 남녀가 순수한 인간으로 만나는 그 순간을 보여주고 싶다. 위대한 모성과 인간애를 보여주려고 한다.