Flash Point is a martial arts, action film. The film takes place in pre-1997, before the return of Hong Kong to the People's Republic of China. As the film opens, brothers Archer, Tony and Tiger are discussing a drug deal with rival gang leader, Sam. Ma Jun, a serious criminal investigations detective, along with a gang of police officers, raids the nightclub for investigation, and winds up fighting against his partner, Wilson, who has been planted a mole.
The three brothers are later attacked by Sam and his gang who are impatient over receiving the drugs from Vietnam. Archer and his brothers later threaten the elder leaders of their gang, when they attempt to intervene. Tiger is later assigned to kill Sam out in public, but the plan backfires when Wilson intervenes. While in hospital, Sam agrees to testify in court against the three brothers. On the night of their mother's birthday, the brothers plan to recover their drug money, but as the heist is being performed, Archer is arrested by Hong Kong police, while Tony and Tiger discover that Wilson is a mole.
While in court, Archer is forced to turn in all of his travel documents, in the hopes that he will not flee from Hong Kong before his hearing. Tony and Tiger brutally murder Sam along with several other witnesses and crime figures crucial to the police's investigation. After their first plan to kill Wilson backfires, Tony and Tiger decide to sneak into a hospital guarded by the Hong Kong Police Department. Ma discovers that Tiger, disguised as a janitor, is in the building and goes after him. Tony, having kidnapped Wilson's girlfriend, Julie, threatens to kill her, if Wilson, now a sole witness, testifies in court. Ma squares off against Tiger inside a restaurant, and brutally beats him to death in front of a crowd after Tiger severely injures a little girl. During the court hearing, Wilson refuses to testify, and the case is dismissed for lack of evidence. Wilson later attempts to rescue Julie, but is captured by Tony and his gang.
Once Archer walks free, Ma holds him captive, and calls his brother, Tony, for an exchange of hostages, leading to a confrontation in a Chinese village. Ma singlehandedly takes on the remaining Triad gang, and engages in a gruelling fight with Tony, who he arrests in the final scene.