A North Korean agent in Berlin is betrayed and cut loose in the midst of a financial espionage intrigue. Together with his wife, a translator at the North Korean embassy in Berlin, they try to escape being purged, as North and South Korean operatives relentlessly pursue them.

Struggling to support herself and teenage daughter, widow Yeon-ju rents out the second floor of her home to Chang-In, who claims to be a novelist working on a new book. The neighbors suspect Chang-In's true identity, as he spends an inordinate time in Yeon-ju's quarters whenever he's left home alone. A battle of wits, charm and various tensions ensue with the trio living under one roof, each harboring their own elaborate motives.