When the son of a gang leader manages to insult the son of a rival gang leader, total war erupts between the rival gangs, and the young hero is forced to do terrible things in order to maintain order and honor.

Undercover cop Leung Foon is having trouble taking down the illegal trading operation headed by crime boss Ferrari. So to accomplish his mission, he asks for help from the renowned Master Wong, an expert in gambling tricks.

The film centralizes on the storyline after Tai Fei (Anthony Wong) obtains branch leader status after Young and Dangerous 4. Tai Fei discovers he has a son, and soon realizes that he is a triad member involved in the Tung Sing gang which deals in narcotics.

Suki is a very devoted gambler. Whenever he goes to Macau, he buys a return ticket in advance, just in case he loses all his money. After breaking up with his girlfriend Cher, who couldn't bear his gambling anymore, Suki meets a girl called Princess Fragrance at a karaoke bar. They later meet again in Macau, both in the hands of a loan shark Brother Face, who threatens to kill them if they don't pay off their debts…

Ting Sau-Ling (Jacqueline Ng) is kidnapped by a gang in Shenzhen but she's rescued by Lau Koon (Robert Mak Tak-Law). The two get to know each other--in order to survive Lau Koon resolutely sneaks into Hong Kong to kill the gang.Ting Kwok-Bo (Lau Dan), gang leader and acquaintance of Lau Koon, pleads to him and sends May (Isabel Leung Pooi-Woo) to be his lover. Tensions rise as the love triangle between Sau-Ling, Lau Koon, and May is complicated by the conspiracies of the gangs of Hong Kong.