Rick Pang, an IPSC champion who is also a gun expert who tinkers with his pistols to perfect his technique known as 'double tap' which is the terminology where a shooter can place two exact shots in the same spot to maximize marksmanship.

A gangster's son is accidentally killed during a drunken dispute with a rival gang, and Officer Milo's task force is assigned to the case. He soon learns that a hitman has been hired to take out the rival gang leader. While Milo and his crew desperately try to find and stop the hired gun, fearing all-out war in the streets, Lai Fu, a smart but inexperienced killer from a small town in the mainland, arrives in Hong Kong to do his job.

Champion competitive marksman Ken comes across an armored van robbery. He sees a policeman held hostage and shoots and kills four of the robbers. One of the robbers escapes and the policeman survives. The case is handled by Jerry Chang, whom Ken knows from having recently beaten him in a shooting match. Ken is found not guilty in court. Soon after, Ken is attacked by the escaped robber Pang Tao. Their confrontation reveals a very different background story and brings about a myriad of lies and traps and changes in relationships as Jerry and Ken try to outsmart each other.