Season synopsis
Contains spoilers for this season and earlier seasons.
A paragliding accident carries South Korean executive Yoon Se-ri across the border into North Korea, where Captain Ri Jeong-hyeok hides her from corrupt officer Cho Cheol-gang. Jeong-hyeok is engaged to cellist Seo Dan, while Se-ri encounters her former fiance, fugitive con man Gu Seung-jun. The village women question her as she plots an escape, while in Seoul Se-ri’s brothers fight over her company and her father registers her as dead. A flashback reveals that Se-ri and Jeong-hyeok crossed paths in Switzerland before the crash. After Se-ri finally returns south, Jeong-hyeok remains behind with the soldiers and villagers she has come to know.
They are separated only briefly. Cheol-gang is convicted on Jeong-hyeok’s evidence, escapes custody and heads south; Jeong-hyeok follows through a tunnel to Seoul, where he reunites with Se-ri. His father dispatches the four soldiers to retrieve him, but they join the couple instead. When Cheol-gang’s men attack, the squad helps fight them off; Se-ri takes a bullet shielding Jeong-hyeok, while Jeong-hyeok and Man-bok shoot Cheol-gang. Se-ri survives surgery. Cheol-gang survives too, but is killed by South Korean security forces in a later confrontation. Her family also learns that her brother and his wife had conspired with Cheol-gang against her, bringing that threat into the open.
The threat is broken, but the lovers cannot make a permanent life together across the border. Jeong-hyeok returns north with the soldiers, and Se-ri resumes life in Seoul. Seung-jun dies protecting Seo Dan, who turns toward music after losing him. Jeong-hyeok is selected as a pianist for the National Symphony Orchestra, and Se-ri sponsors an annual musical visit to Switzerland so they can meet there. They reunite for two weeks each year, continuing their relationship without permanently moving to either side of the border.