A trio of reformed juvenile delinquents work as undercover cops.
Cast:Michael Cole , Clarence Williams III , Peggy Lipton , Tige Andrews , Simon Scott , Ross Elliott , Bob Golden , Rex Holman , Linda Marsh , Arthur Franz , Norman Alden , Woodrow Parfrey , Murray MacLeod , Brooke Bundy , John Dennis , Bill Zuckert , Harry Basch , Frank Farmer
Capt. Greer reluctantly enlists the aid of a psychic to help find a kidnapped coed.
Julie takes in a young, apparently destitute, Mexican boy, not realizing that he is connected to a couple of thieves who don't want him talking to the wrong people.
The widow of an FBI agent, who is dating Greer, is kidnapped by a narcotics gang.
While on vacation Pete befriends a woman who tells him her brother is missing. When she is found dead he's charged with her murder.
Linc is initially bummed about having to get his driver's license renewed until he meets the examiner. They start dating but a man from her past comes back into her life and causes problems.
After the police commissioner's sister is the apparent target of a killer Greer and the Squad are assigned to watch over her.
During a campus demonstration a student protester is found dead. The protesters think he was killed by the police and the police think he was killed by another student.
During a botched robbery Willie falls down an elevator shaft. In the hospital they discover he's illiterate and try to help him learn to read and move beyond a life of crime. But his partner in crime doesn't want him talking to the cops.
Julie goes undercover as a country singer at a wayside inn while Pete and Linc investigate the suspicious death of a faded country-western star.
Pete, Linc and Julie go undercover at Sims College to investigate a frat boy's mysterious death. Pete plays a running back, Linc an African exchange student, and Julie the object of desire for the star quarterback.
The Mod Squad sets to work busting an extortion racket run by a self-styled healer responsible for the death of Linc's friend. Julie befriends a wheelchair-bound man paying large sums for empty promises that his paralysis will be cured.
When Pete and Linc's friend Sol Alpert (who survived a plane crash with them and Captain Greer in the first season episode "Flight Five Doesn't Answer") finds his business vandalized, he then learns it was done in protest over living conditions in ghetto housing owned by his own cousin. Sol decides to fight his cousin to get improvements in the housing, and with Pete, Linc, and Julie's help decides to bring the matter to a Jewish court.
Pete, Linc, and Julie go undercover to trap a suave, charming veteran con man. His latest targets are three gullible elderly widows.
Pete searches for a young man who saved him from a beating by muggers, but then ran off when he discovered he was a cop. He finds that the young man is trying to look for his father, who has escaped from an institution and may be planning to come after a businessman who cheated him.
Julie is kidnapped and held for ransom by a disturbed young man who has mistaken her for her friend, the daughter of a wealthy woman whom he wants to punish for insulting him.
Chief Metcalf asks the squad to find his daughter, who has left home despondent after the death of her fiancé in Vietnam. They find her, addicted to drugs and part of a decadent rock star's coterie.
While on a motorcycle trip to Mexico, Pete and Linc are detoured by a biker gang into a border town and held hostage along with all of the town's residents. The gang refuses to leave until they find out who in the town killed two of their members.
Julie becomes romantically involved with a foreign exchange student from a Middle Eastern country which is in political turmoil, not knowing that he is actually the son of the country's king and that his life is in danger from his father's opponents.
Sammy Davis Jr. plays Billy Lee Watson, a recovered drug addict who is accused of statutory rape by his alleged victim's father, who wants to close down the halfway house Billy has been appointed director of. Billy was trying to help the girl, who is herself addicted, and pregnant.
A young nun sees her gangster father commit a murder, but blanks out the memory of it. Unfortunately, higher-ups in the syndicate learn of it and decide to have her hit.
As the trio reminisces over two years together, and Pete considers quitting the group to work with his father, an old nemesis arrives: Beau Graves, one of those they helped put in jail in the premier episode. He has just been paroled and has come seeking revenge against the trio.
Janny Wills, first introduced in the first season episode "A Hint Of Darkness, A Hint Of Light", invites Linc, Pete, and Julie to meet her new fiancé, Dr. Frank Tarver. Tarver doesn't tell them that he is being threatened by a man blaming him for his daughter's death. But when the trio investigates further, they find that Tarver may not be who he seems.
Pete visits his Beverly Hills home to try to help his old girlfriend, who believes her father is being kept in a mental ward against his will and manipulated by her uncle and cousin. While there, Pete also reunites with his mother.
Pete, Linc, and Julie go undercover working on a film project on which strange accidents have occurred. The film is based on a twenty-year old murder mystery, and the director believes the real killer is trying to sabotage it because he fears his identity will be revealed.
After he tries to stop a runaway car, the son of a former cop and friend of Captain Greer is charged with stealing the vehicle. Then it is learned that the car, which belonged to a judicial candidate's campaign worker, was also involved in a hit-and-run. The trio goes undercover at the candidate's headquarters to further investigate.