During the peaceful years of the Daming Dynasty, Yuan Mo, a commoner from Changle City, stands at the city gates issuing permits to foreign visitors, using the Four Square Pavilion's seal. Unexpectedly, he encounters A Shu, a refugee from Yanle Kingdom trying to sneak into the city, which leads to an altercation. This results in the newly arrived border general Wang Kunwu being punished by overseeing duties at the Four Square Pavilion. As a consequence, Yuan Mo is inadvertently pulled into the affairs of the Four Square Pavilion's western office, overseen by Yu De Shui. He becomes a minor official handling various international affairs. Through a series of serendipitous events, A Shu becomes Yuan Mo's "little maidservant," Wang Kunwu becomes his superior, and the formidable Yuchi Hua, a noblewoman with power, joins the mix. Mocked as a "useless" member of the western office, Yuan Mo matures as he navigates through challenging diplomatic matters.