Principal Investigator of the ICAC, William Luk (Louis Koo), and Chief Investigator, Ching Tak Ming (Kevin Cheng) are investigating a smuggling and corruption case. During the investigation, they discover another customs corruption case involving human trafficking unexpectedly. Such case involves King (Rosyam Nor), the head of an international crime syndicate, Siu Cheuk Ah (Michael Tse Tin Wah), the mastermind, Ching Fai Hung (Bosco Wong), the younger brother of Ching Tak Ming who works in customs, and Judge Emma Pong (Jessica Hsuan), the chief justice of Asia, who is being secretly protected by G4 Lau Po Keung (Cheung Chi Lam Julian) in Hong Kong. The case has never been more complicated. William Luk is facing unprecedented pressure and challenges. Lau Po Keung fights against gangsters to keep Judge Emma Pong safe in the busy city. Ching Tak Ming must choose between family affection and justice...