In Hong Kong, triads and various police units have contaminated each other with spies up to the roof. Detective Ming, who once started in the civil service as an undercover agent in the service of the underworld godfather Sam, has discovered his heart for the bourgeoisie, so to speak, after eliminating his counterpart Lau and mercilessly pursues all moles in the police. In doing so, he makes use of the files of a police psychologist in love and thus learns more about Lau's story.