Baretta hunts down the mob boss who wanted Tony's girlfriend murdered.
Baretta must protect a friend's pregnant widow from her husband's killers and her drug habit.
According to police records, paroled female convict Virginia Marriott (Ann Coleman) has committed suicide. Thus, when Virginia's parole officer sees the girl, very much alive, wandering near the harbor, he is amazed. But not for long: The officer is promptly murdered, bringing maverick undercover cop Tony Baretta (Robert Blake) into the case.
Tony Baretta (Robert Blake) maintains a 24-hour surveillance on drug kingpin Durone (John Marley), who is expecting a multi-million-dollar shipment. Durone knows that he's being watched, and Baretta knows that he knows. The relentless undercover cop is also fully aware that Durone is in mourning for his recently deceased wife, a fact that Baretta hopes will break the aging drug lord's spirit.
Much against his better judgment, undercover cop Tony Baretta (Robert Blake) allows his girlfriend Andrea (Ann Prentiss), a freelance photographer, to tag along with him on his latest investigation. Somewhere along the line, Andrea stumbles upon a sack containing 500,000 dollars in Syndicate money. Hoping to scoop her journalistic rivals, the girl discreetly hides the loot, thereby virtually signing a death warrant for herself and Baretta.
Baretta becomes interested in a case when he discovers that there is no record before the age of 20 for the dead wife of a prominent attorney.
A teenage brother of a drug pusher wants revenge on Baretta for his shooting death.
After Baretta's partner takes a bribe, Tony is put in front of a committee on police corruption to investigate him.
Baretta portrays a gangster on the run to get inside of a brothel run by the syndicate, after a policewoman is murdered.
Baretta discovers that the rash of petty burglaries is being committed by a mentally challenged friend who is copying Robin Hood.
Baretta believes the girlfriend of a mobster is too scared to confirm his alibi, which may land him in prison for the death of his mob boss.
When an heiress becomes missing, Baretta begins an investigation of her affluent friends which causes Tony to feel out of his element.