A senior official at the ministerial level in the mainland is suspected of assigning his mistress to come to Hong Kong to launder money in huge amounts. For this reason, ICAC (Independent Commission Against Corruption) Luk Chi-lam (Louis Koo) and JFIU (Joint Financial Intelligence Unit) Lau Po-keung (Julian Cheung) jointly launched an investigation. But at this time, Luk was accused of having huge amounts of property of unknown origin and was investigated by ICAC L Group (Internal Disciplinary Investigation Unit) Cheng Deming (Kelly Cheng), and was eventually suspended. In order to prove his innocence, Luk Chi-lam tried every means to find the girl Eva (Stephy Tang) who reported him, and found that all this was closely related to the money laundering case under investigation. Not long after, Hong Liang (Ding Haifeng), director of the Investigation Department of the Anti-Corruption Bureau of China, also came to Hong Kong, and his target was Minister Zhang (Feng Lei), the mastermind behind the money laundering case. The two sides of the strait are linked, and multiple departments are cooperating to fight a desperate battle with evil forces...