Marcus Burnett and Mike Lowrey are detective sergeants in the Miami-Dade Police Department.
While Lowrey is from a wealthy background and enjoys a playboy-like lifestyle, the slightly older Burnett is married, with three kids.
One night, $100 million of seized heroin is stolen by gangsters from a secure police vault. This is a major blow to Burnett and Lowrey, because it was the biggest drug bust of their careers. Internal Affairs believe it was an inside job and issue an ultimatum—if they do not recover the drugs in five days, the narcotics division will be shut down.
It is quickly discovered that one of the gang members was Eddie Domínguez, a former cop, who has absconded with some of the heroin. Dominguez is shot to death by his boss, French drug kingpin Fouchet, who also kills escort girl Max, one of Lowrey's ex-girlfriends. The only witness to the crime is Max' friend Julie Mott.
Although she has never met him, Julie will only testify to Lowrey, but he is out of contact when she threatens to run, so Burnett is forced to impersonate him in order to get her to co-operate.
Eventually, Fouchet and his gang of criminals learn where Julie is and kidnap her.