Infernal Affairs

Cheung Sung-bong is a highly respected cop with a long history of success in dangerous cases. However, his past soon comes back to haunt him when a former protégé resurfaces, seeking revenge.

A police detective's investigation of a prostitute's murder points to his best friend.

Liu Yue Ping reports to the ICAC about a rich 2G Cao Yuen Yuen who bribed officers of the Hong Kong Correctional Services (HKCS) from inside the prison. William Luk decides to infiltrate the prison as an inmate to conduct his investigation, while his partner Ching Tak Ming and Chief Inspector Lau Po-keung back him up from the outside.

Hoping to raise enough capital to finance a legitimate business and leave behind his life of crime, Liverpool underworld boss Ged Brennan sends his brother Ratter and a crew to pull a daring final heist. But when Ratter kills a drug kingpin during the job, Brennan must turn to rival crook Franner to avert an all-out gangland war.