- Laughing (Michael Tse) is formally a police undercover. However due to a drug trafficking case, Officer Pun (Felix Wong) is hot on his trails.
Before Laughing becomes a police undercover, he works under triad Brother One (Anthony Wong). Brother One treats Laughing as his own brother, however to protect his territory and illegal businesses, Brother One instructed Laughing to join the police force and act as his undercover.
Laughing is a high-flyer in the police academy. However he never got a chance to join the force because he is specially picked by Officer Xian (Yuen Biao) to be an undercover in the underworld syndicate. Hence Laughing becomes a “double-undercover".
Brother One is happy that Laughing is allocated to the triad of his rival (Francis Ng). To make his situation worse, Laughing falls in love with the triad leader’s sister, Karen (Fala Chen).
Justice, brotherhood and love, what will Laughing decide on? His decision will be a turning point in his life.