A half a million dollars is stolen from the American Mafia by its bookkeeper Harry Mitchell, who splits it with capo di tutti capo Dano Villanova's girlfriend Stacey Woodward. Each goes separately into hiding.
Sol Madrid, an undercover US government narc, is assigned to find the pair, hoping to persuade Mitchell to testify against organized crime in court.
Madrid finds Woodward first, and, posing as a high-level drug dealer, takes her to Acapulco. He approaches big time heroin producer Dietrich and proposes going into business together, offering to smuggle Dietrich's drugs into the US for half the profits. Mitchell is Dietrich's house guest.
American law official Jalisco, a Mexican native, is assigned to help Madrid.
When Woodward's whereabouts are discovered by Villanova, Madrid relocate her to his yacht for safety. Villanova tracks her there, has her kidnapped, and in revenge for both her leaving him and ending up with half the stolen money, shoots her up with dope until she becomes an addict.