One day, while Yoon Se-ri is paragliding in Seoul, a sudden tornado blows her off course and knocks her out. She awakens to find her paraglide hanging in a tree in a forest in the North Korean portion of the DMZ. There she meets Ri Jeong-hyeok, who eventually gives her shelter and develops plans to help her return to South Korea secretly. Over time, they fall in love, despite the divide between their respective countries. Back in South Korea, Yoon Se-ri's family suppresses the news of her disappearance, fearing it will depress the stock price of Queens Group. Just before Se-ri went missing, her retiring father had told his family that he intended to make her his successor, based on her ability as a businesswoman, which she proved by building her own company, Seri's Choice. Her half-brothers, Yoon Se-jun and Yoon Se-hyung, each hoped to be their father's replacement but they have struggled to manage the subsidiaries under their control. The brothers are supported by equally-ambitious wives, Do Hye-ji and Go Sang-ah, respectively. In Se-ri's absence, Se-hyung uses unscrupulous means to win the succession battle, while his wife Sang-ah attempts to take over Se-ri's Choice. Se-ri and Jeong-hyeok's story is intertwined with that of Seo Dan and Gu Seung-jun. Dan is the sophisticated daughter of a wealthy North Korean department store owner. She has been studying the cello in Russia for several years but returns to marry Jeong-hyeok, to whom she is engaged through an arranged marriage though they have only met a few times. As she returns to Pyongyang, she crosses paths more than once with Gu Seung-jun, who has fled to North Korea (with the protection of corrupt North Korean officials) in order to escape the pursuit of Se-hyung, under whose incompetent watch he had embezzled large amounts of funds. The first half of the story (episodes 1–9) follows Jeong-hyeok's attempts to hide Se-ri and facilitate her return to South Korea. They are impeded by Cho Cheol-gang, a corrupt and ruthless officer from the Ministry of State Security, who previously arranged the murder of Jeong-hyeok's elder brother, an officer who tried to expose him for crimes against the North Korean regime. Jeong-hyeok's attachment to Se-ri distresses not only Dan, his fiancée, but also his father, a high-ranking political figure. If it became known that Jeong-hyeok harbored a South Korean citizen, it could be used by rival officials to ruin their family. In the second half of the story (episodes 10–16), Se-ri has returned to South Korea and resumes leadership of her company, surprising her family and others who had thought her dead. Cheol-gang is convicted and sentenced to life imprisonment but escapes custody and infiltrates South Korea to go after Se-ri for revenge. Jeong-hyeok goes to South Korea to protect Se-ri from Cheol-gang. His subordinates follow, sent to Seoul by his father to retrieve him. Meanwhile, in North Korea, despite hostile initial encounters, Dan and Seung-jun fall in love and she shelters him when corrupt officers betray him to Se-hyung's gangsters.
