Boxer Kid Calico is told to throw a fight in order to keep his kidnapped father alive.

A gang member is remanded into the judge's custody only to stay in the guest house with Mark, while the judge and Mark go after a psychiatrist who has been taping private sessions with clients revealing vital damaging information.

Hardcastle & McCormick travel to Rio to track down a drug runner.

The judge inherits a rather short race horse.

Robert Culp guest stars as Arthur Farnel, an ex-con who runs a school leading and teaching their students how to break the law. Mark decides to go undercover in order to gather enough evidence to put him away.

Hardcastle returns to his hometown in Arkansas for a high school reunion, only to learn from an old friend that people are being swindled out of their farms. After the friend is murdered, and his daughter asks the judge for help, Hardcastle enlists McCormick to burglarize the local land office.

Mark and Hardcastle take a group of misfit kids to a local prison in order to scare them straight; but while they are there, they are taken hostages by prisoners who are frustrated because of the repeated abuse from the guards and the warden.

After telling his poker buddies to clean up the house before he gets back from the airport with the judge, McCormick returns with Hardcastle to discover that everything valuable on the estate has been stolen, including all of the judge's files on past cases.

The proposed destruction of a popular college bar brings Hardcastle's niece in the spotlight. With her protests making him upset, he must put aside their differences when she narrowly avoids a kidnapping.

Jesse Wingo, the former famous singer, is spotted by McCormick at a talent contest. But when approached about his past, the contestant reveals his name to be Sam Jones. Puzzled at the similarities, Mark investigates the man only to find that other people are looking for the man named Sam Jones, but want him dead.

Perplexed by the apparent suicide of ex-con Denny Frye, an up-and-coming comic, Hardcastle decides to investigate. Thanks to Mark, Hardcastle discovers that Denny was romantically involved with a woman named Pamela Bayer. The judge's earlier suspicions gain some validity when Hardcastle and McCormick see a group of men try to kidnap Pamela. After rescuing Pamela, Hardcastle and McCormick learn that the prospective kidnappers work for reputed mobster Sonny Austin, her ex-boyfriend. Realizing that Sonny, in an irrational attempt to win back his ex-girlfriend, has been assaulting all Pamela's dates, Hardcastle and McCormick try to find out who has been providing the mobster with her dating schedule. It turns out that Pamela has been primarily dating comedians employed at Boots Dikeman's club. Figuring that Leo Dikeman, Boots' main competitor, is probably encouraging Sonny, Hardcastle and McCormick decide to pay him a visit. Before they arrive, Sonny, realizing that he has been used, kills Leo. Facing a dead end in the case, the judge asks Mark to pose as one of Pamela's comedian boyfriends. Taking the bait, Sonny falls into the judge's trap.

Mark is thrilled when he wins $20,000 racing in the Arizona Modified. His joy quickly dissipates when thieves hold him up and steal his winnings as well as the Coyote. Based on Hardcastle and McCormick's description of the thieves, Deputy Sheriff Dan Johnson realizes that they were robbed by locals Arvin Lee and Melissa Kantwell. Complicating matters is the fact that Melissa is the wife of Billy Blackstone, the city's sheriff. After recovering the Coyote from a used car salesman, Hardcastle and McCormick begin to track the crooks. To their surprise, they catch up with Arvin Lee only to discover that he has been murdered. Putting the pieces together, they realize that Blackstone probably killed Arvin Lee. Taking their theory one step further, Hardcastle and McCormick speculate that Melissa only pretended to fall in love with Arvin Lee in order to trick him into stealing for her. With Johnson's help, the judge and Mark locate Blackstone and Melissa. With Blackstone unwilling to surrender, the deputies are forced to shoot and kill him. To Mark's regret, the shoot-out starts a fire that destroys his racing winnings.

With the judge's birthday coming up, Mark decides to unofficially help him close a cold case related to a soon-to-be-paroled crimial that Hardcastle put in jail for another crime. Unfortunately, the new trial winds up with Hardcastle being shot and the criminal escaping.

In the third season opener, Hardcastle and McCormick go on a photo exhibition with Buzz Bird, one of the judge's old friends. To their regret, Buzz, who is a pilot, has a heart attack while flying them over a stretch of Oregon wilderness. While Hardcastle and McCormick survive the crash landing, they are stranded miles from civilization and unknowingly attract the attention of Taylor Walsh, a mountain "pirate" who has made his living by robbing tourists. After suffering through a horrible rain storm, Hardcastle decides to tell Mark how much he appreciates their friendship. Although Mark pretends to be asleep, he actually hears everything the judge has to say. The next day, the two men come across the dead body of a murdered man. Realizing that they are being tracked, they decide to speed up their journey by white water rafting. Once the two men are in the water, Taylor and his men attack. Fleeing to land, Hardcastle and McCormick manage to evade the pirates. Turning the tables, the two men capture Taylor and his men. A month later, the judge and Mark, with their prisoners in tow, finally return to civilization.

Although Hardcastle is initially pleased to be invited to a party on a private train, his emotion changes to anger when he discovers that he has been lured onto the train under false pretenses. His ire is further raised upon discovering that the train is not scheduled to stop for another day. One small consolation: Mark, accidentally trapped on board the train, is around to help him find out what is going on with the trip. The mystery takes a deadly turn when one of the passengers is murdered. Although the unknown murderer temporarily manages to get rid of Mark by throwing him off the train, the ex-race car driver, who is unable to identify his assailant, pools his resources and returns to the train down the track. Another murder prompts Hardcastle to set a trap for the killer. While Hardcastle pretends to be a victim, Mark purposely lets slip that the judge had obtained evidence against the killer. Taking the bait, passenger Carl Sharples tries to search Hardcastle's "body". Exposed as the killer, Carl reveals that he has been eliminating the people (strict teacher, ex-girlfriend, army commander, high school coach, that he selfishly believes "ruined" his life. With Mark's help, Hardcastle stops Carl before he can hurt anyone else.

Cleaning out his shed, Hardcastle comes across an old trophy belonging to Teddy Hendrix, his college roommate. Deciding to visit Teddy, who is now a basketball coach, Hardcastle walks into an attempted kidnapping. Since Teddy flees the scene before he has a chance to confront him, the judge visits his old friend's wife. Thanks to Fran Hendrix, Hardcastle discovers that Teddy has been having a disagreement with a man named Roy Barlow. Realizing that his best chance of solving his problems lays with the judge, Teddy decides to tell Hardcastle about how he has been fixing basketball games. Agreeing to help his friend come clean, Hardcastle arranges a meeting between Teddy and the district attorney's office. Before Teddy can testify, Fran, who has secretly joined forces with Barlow, lures her husband into a trap. Meanwhile, Fran also helps Barlow capture Hardcastle. Thanks to Mark and their old basketball team buddies, Hardcastle and Teddy are rescued. Additionally, Mark and the former team members capture Fran and Barlow.