In a high-stakes corruption case, ICAC Principal Investigator Kong Kin-chau edges closer to the truth within a listed company. Chief Investigator Szeto Kai-man and Assistant Investigator Ting Sum go undercover as a father-daughter duo to gather evidence against a construction firm, while Firearms Team member Chui Ho-nam and Assistant Investigator Chung Hau-ling help secure crucial intel. Meanwhile, Senior Investigator Ng Hok-bun exposes corruption within the prison system. Despite differing views and setbacks, the team remains steadfast in pursuing justice in the secondary school engineering scandal.
Kan Yiu-yeung, Ku Ka-keung, Kiu Po-po and Kiu Tai-nam were once CTRU’s Formidable Quartet. An incorrect decision in an operation caused the breakup of their friendship. And the quartet went their separate ways. Fast-forward to the present and an indiscriminate homicide again brings the quartet together. But there are still certain unresolved issues between themselves. POTT is Counter Terrorism Intelligence Cadre’s other elite task force. Team leader Fong Kwok-hei admires Po-po and asks her to become her subordinate. Team member To Siu-jie fancies her partner Yiu-yeung and finds out Po-po is Yiu-yeung’s ex-lover, so she “starts a war”. Successive explosions happen in the city. While investigating, Po-po asks prisoner-cum-hard criminal Dr. Hong’s for help, and the process is surprisingly easy. Actually, Dr. Hong has some trick up his sleeve.