Johnny To's police drama PTU details the ramifications of an officer losing his weapon. Seargant Lo (Lam Suet), head of the police anti-crime division, finds his gun missing after an altercation with a gang. Police Tactical Unit (PTU) team leader Mike Ho (Simon Yam), not wanting to get the soon-to-be-promoted Lo in hot water, gives him some time to recover the firearm. While Li and Mike attempt to find the gun before the gang kills anyone with it, police investigators suspect that there may be corruption within the PTU. To filmed the picture off-and-on for over two years before it played at the 2003 Berlin Film Festival.