Teresa,Wong Cheuk-Ling Ruby,Lam Suet,Chen Wen Lian
Kammy was raised in Po Leung Kuk and admitted to the Police Academy. Her background appeals to Inspector Lo, who dismisses her and sends her to the triad as an undercover.
Mui's father was a cop who was so indulged in gambling. Mui had no choice but to go undercover in the police force to help the King of Drugs Kuen, so as to keep her father's unscrupulous work a secret.
Lo and Mui are about to crack down a drug trafficking deal in an operation. Kuen receives intelligence and thus terminates the deal right away. The operation fails. Both Lo and Kuen come to realize the existence of an undercover sent from the other party, and they both swear to pick the guy out...