Narcotics detectives Mike Lowrey (Smith) and Marcus Burnett (Lawrence) have been assigned to a high-tech task force investigating the flow of designer ecstasy into Miami. Their inquiries inadvertently lead them to a major conspiracy involving a vicious kingpin (Jordi Molla), whose ambitions to take over the city's drug trade have ignited a bloody turf war. But Mike and Marcus' friendship and working relationship is threatened when Mike begins to develop feelings for Marcus' sister Syd!