Saam cha hau (2005)

This thriller has Suen chasing some gangsters around Hong Kong. One of his key witnesses is assassinated after being extradited from Canada and that puts an end to the prosecution's case. Meanwhile, Suen is still struggling with his girlfriends disappearance 10 years ago. A pair of assassins fill out the third plot chain. The gangsters, Suen, and the assassins intersect often as they try to solve the crimes and find out what happened to Suen's girlfriend.