Luk (Louis Koo) and Ching (Kevin Cheng) were working on a Customs corruption case. They found out the case was linked to King, the leader of an international human trafficking group, which also involved Emma Pong (Jessica Hsuan), the Chief Justice of South East Asia. Luk and Ching, together with Chief Inspector Lau Po-keung (Julian Cheung), were determined to bring King to justice.