Hong Kong Police Force Superintendent Wong Chi-Shing meets his Triad informant, Hon Sam. Meanwhile, Lau Kin-Ming, who is due to become Hon's prospective spy within the Hong Kong Police Force, assassinates Hon's Triad boss, Ngai Kwun, in a mission for Hon's wife, Mary, who wants Hon to rise up the triad ranks. Mary tells Lau to keep her order secret from all, including Hon.
