On a night of heavy rain, a young woman was killed in a car accident. When Gurisheng Gonghe (Takuya Kimura) and Chikako Asagi (Keiko Kitagawa) conducted routine inquiries on the driver involved in the accident, Maiko Amamiya (Takako Matsu), a prosecutor from the Namba Branch of the Osaka District Public Prosecutors Office, unexpectedly appeared in front of Gurisheng. It turned out that the deceased was related to a gangster intimidation case that Maiko was investigating. All signs indicate that there are unknown secrets behind the car accident on a rainy night. The persistent Gurisheng and his partners went to the scene to investigate, and they were actually involved with the Embassy of the Principality of Neustria. Because the embassy enjoys extraterritorial jurisdiction, the Japanese prosecution system cannot obtain the cooperation of the other party at all. After that, Gurisheng and others encountered death threats one after another, and the heavy doubts could not dispel the stubborn man's idea of finding the truth. He and his partners bravely moved forward along a thorny road...