Independent Commission Against Corruption (Hong Kong) (ICAC) investigator William Luk (Louis Koo) and Joint Financial Intelligence Unit (JFIU) officer Lau Po-keung (Julian Cheung) are respectively investigating a corruption and money laundering case both involving Customs and Excise Department (Hong Kong) officer Tik Wai-kit (Michael Tse), but are unable to find any clues. At this time, Ching Tak-ming (Kevin Cheng) of ICAC's L Team (Internal Disciplinary Investigation Team) receives a report from Eva Ng (Stephy Tang), claiming Luk has accepted a bribe of HK$12 million. Unable to provide an explanation, Luk was immediately suspended from his duties.