The Stool Pigeon (2010)

Cast: Nicholas Tse Ting-Fung, Nick Cheung Ka-Fai, Gwei Lun-Mei, Miao Pu, Liu Kai-Chi, Lu Yi, Philip Keung Ho-Man, Lau Kong, Lawrence Cheng Tan-Shui, Sherman Chung Shu-Man

Living in the guilt of sacrificing his informant in a previous operation, Criminal Intelligence Inspector Don Lee is wary when his superior orders him to send another informant to spy on the criminal …