The story begins with the opening of the Hong Kong Victoria Harbour tunnel by business partners Paul Wagner and Nigel Griffith. Paul attends with his wife, and their twin infant sons, Chad and Alex. However, after the celebrations, the family is foll...

The story begins with the opening of the Hong Kong Victoria Harbour tunnel by business partners Paul Wagner and Nigel Griffith. Paul attends with his wife, and their twin infant sons, Chad and Alex. However, after the celebrations, the family is followed home by a Triad hit squad on orders from Griffith and crime lord Raymond Zhang. A shootout ensues, in which Paul and some henchmen are killed. Paul's wife begs them to spare the kids but is killed by Moon (Bolo Yeung), the top henchman. Chad is rescued by the family bodyguard, Frank Avery, and raised abroad. Alex is dropped off on the doorstep of a Hong Kong orphanage by the family maid. In the present day, Chad and Frank are running a successful martial arts business in Los Angeles when Frank reveals a new 'business' for the two of them in Hong Kong. Frank also tells a surprised Chad that he is not his uncle. Soon after arrival, they find Chad's long-lost twin brother Alex and Frank explains their shared past. It is revealed that Alex would never wear black silk underwear, the only discernible difference between the identical twins. Alex also has a girlfriend who works for Griffith’s company, Danielle Wilde. After escaping the Hong Kong Marine Police for trying to illegally sell foreign cars with electronics inside, Chad (mistaken for Alex) is taken in by the Triads to discuss the incident. During the interrogation, Chad learns about a drug lab in Causeway Bay. Alex and Chad arrange to destroy the lab by planting C4 in the complex one night, but Chad's clumsiness triggers a massive gunfight. The lab is destroyed, but Alex loses any respect for Chad. Later, Danielle and Alex talk on a ferry and discuss a meeting that will take place soon in a night club in Hong Kong, with Zhang and other bosses in attendance. Alex, Chad and Frank endure their third mission to take down Zhang using Cognac boxes with C4 encased in them...