The story takes place in 1930 in Shanghai, where underworld forces are rampant. The romantic detective Tian Jiye accidentally intervened in a prostitute murder case, and the suspect turned out to be He Rushi, his first love girlfriend whom he had abandoned. During the investigation, Tian Jiye gradually unearthed the huge political conspiracy and corruption hidden behind the case. His former life and death brother, Li Bingjun, the current spy chief, was also involved. The whirlpool of emotions and the dark road put him in a desperate situation. At the moment when his life was hanging by a thread, he received support from revolutionaries and was determined to find the root of the crime - a snuff bottle containing a list of Japanese spies. After bidding farewell to He Rushi, Tian Jiye prepared to greet the rainstorm with blood and wash away the darkness before dawn.