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.
Guest star 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---and is actually Billy's daughter.
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.
While staking out a warehouse robbery, Pete accidentally injures a young woman named Billie. Guilt-ridden, he falls in love with Billie, an aspiring folk singer with a hauntingly beautiful voice. Things become unexpectedly complicated when Billie's brother, Case, is one of the robbery suspects. Case learns that Pete is an undercover cop and, desperate for money, demands that Billie get the goods on Pete to lead them to a big robbery.
Linc receives a desperate call from an old friend, now an inmate at a mental institution. Shortly afterward, the friend is dead of "heart failure", only the latest of a number of strange deaths at the place. Linc goes undercover as a patient at the institution, hoping to find out what's going on.
A hard-nosed ex-cop returns from Vietnam to investigate the death of his brother, who was killed in a car accident just after he called him and told him that he had seen a murder, and that the murderer was an undercover cop.
The trio becomes involved in the case of a young boy who's being raised in an orphanage. His mother is not taking care of him, but she does not want to give him up for adoption, and she is involved with a drug dealer.
Pete is knocked out and jailed in a small town when he tries to assist Levi Frazee, an Indian who is believed to be withholding the whereabouts of his cousin, who is suspected of murder. Later the main witness, the victim's wife, changes her story and claims it was Levi who killed her husband.
Linc comes to the airport to meet a friend who is returning from Vietnam, only to learn that he was killed by a sniper on the day he was supposed to go home. Suspicious of the story of how his friend died, he wonders if any of the four other servicemen in his unit who have returned know more than they are telling.
Julie is staying at a beach house where she is helped by a kind old fisherman who lives nearby. He tells her to ring her porch bell whenever she needs his help. When she visits his house the next day, someone else lives in the house. She can't find the mysterious old fisherman except when she rings the bell, he suddenly shows up. Is he for real or a figment of Julie's imagination?
The head of a local campus ROTC is murdered, and the main suspect is the man's mentally disabled teenage son, whom he had frequently beaten. However, Pete and Linc, who have befriended the youth, believe he is innocent.
Julie is forced at gunpoint to drive Cliff Hansen and his young son to Los Angeles. Cliff has kidnapped his son to take him away from the influence of his wealthy father-in-law. However, both Cliff and his son have been exposed to Rocky Mountain Spotted Fever, and need medical attention as soon as possible.
The trio search for an illegal immigrant, a friend of Pete's who ran after an immigration officer was seriously injured while trying to apprehend him. Complicating their search is a stubborn police lieutenant, who comes from the same Mexican town as the immigrant, and who regards the trio as interfering. The cop, it turns out, may be involved himself in helping people enter the U.S. illegally.