A major drug dealer that's being investigated and his ruthless partner, a brothel madam, frame a professional jai alai player for murder of a prostitute to blackmail the athlete's customs agent brother into selling Crockett and Tubbs out.
Crockett and Tubbs are working on nailing a Bolivian drug dealer. When something goes wrong at the meeting, the Bolivian loses something very important to him and he won't deal until it's returned to him. They discover that an old man who was at the meeting has it. He tries to sell it back but the Bolivian won't agree to that. One of his people tries to get it back but the old man proves to be tough. Crockett and Tubbs offers to act his intermediary but the old man insists on being involved. They later learn that the old man is a Texas Ranger.
Tubbs' attempts to stop synthetic cocaine of the highest purity from hitting the streets are threatened by his ex-NYPD-partner, whose career was destroyed by Tubbs' testimony regarding a confused shooting.
The team learns of a baby selling ring when one of the children's mother comes to Miami looking for her child. The trail leads them to a sleazy lawyer. When the lawyer manages to tie up any loose ends. They decide to use the mother to trap him.
A prostitution bust at a motel snares an officer from another precinct. Castillo wants to take his badge, but Crockett haves him hold off and uses the officer to find the source of pure cocaine found on one of the prostitutes, a girl the wayward cop is in love with.
When some prostitutes are being killed, Castillo recognizes the M.O. as similar to some killings he saw when he was in Vietnam and working with a Vietnamese investigator. And the investigator shows up in Miami.
Crockett plans to marry his latest girlfriend, an ER doctor from the UK. However, she has a dark secret. A major drug dealer whom Sonny has recently busted uses it to both free himself and make Crockett look dirty.
Tubbs wins a free vacation and he brings his girlfriend with him. But when he arrives, he discovers a man he arrested. He eventually learns that he's been set up by Calderone, who is arriving on the next plane. Tubbs is trapped and with no weapon and no one is willing to help him. He also eventually discovers another woman he knew who is now with Calderone.
Crockett and Tubbs along with a couple of other cops were about to make a bust but instead are ambushed and one of the cops is killed. It seems that this was not the first time this happened. It's evident that someone on the inside is giving dealers info on busts. Tubbs then loses it. Later he is approached by a cop who wants him to work with him. The partner of the cop who was killed is determined to find out what happened. And when he sees Tubbs with the cop, he follows him.
A call girl witnesses two henchmen take her client and ultimately murder him, causing her to go into hiding, confiding and staying with a friend, a woman Crockett falls for big time. Unknown to him, there is far more to her than he knows.
While Crockett and Tubbs are meeting with a dealer, some men wearing DEA gear come in and take the cash and drugs. But the DEA is not admitting to anything. Later more incidents occur. In the meantime, an Internal Affairs man believes that Crockett may have turned and is determined to take him down. Crockett decides to talk to someone he knows in the DEA, who unknown to him is the one responsible.
A member of a violent biker gang is accidentally killed during a drug sting by Crockett. The other members of his biker gang avenge his death by killing everybody that may have been a part of it until they find the wire.
The team is working on a Cuban named Pedroza. They discover another man keeping tabs on him. They learn that he's a Communist agent. He goes to see Gina and tells her that he knew her mother when she was still in Cuba and that she was murdered by a jealous ex-lover, Pedroza.