Barnaby Jones and Frank Cannon continue to work together to unravel a deadly conspiracy to cover-up corporate wrong doing and several related murders. Meanwhile, Betty goes undercover to help them crack the case despite the dangers.
An aging star of the stage trying to make a comeback is being terrorized by someone who doesn't want to see that happen. Barnaby is hired by her agent to sift through the long list of possible suspects.
A mentally unstable young man who was declared innocent of murder by reason of insanity several years ago is once again suspected of murder. It's up to Barnaby to prove him innocent of being who authorities are calling "The Orchid Killer".
Barnaby looks into the alleged accidental death of an investigative reporter and soon discovers that it is a case of murder. He also believes that there may be another murder directly related to the case.
After a man's wife disappears on their wedding day the concerned husband asks Barnaby to look into what may have prompted her to run away. While investigating Barnaby discovers the bride has a dangerous past that has come back to haunt her.
Sabotage leads to murder when competing teams within a military weapons contractor try to develop a new missile guidance system. Barnaby discovers a couple of love affairs involving team leaders and the bosses wife may also be part of the motive for murder.
An airline stewardess is an unsuspecting mule to smuggle heroin into the country for her boyfriend and his partner. After she discovers what's going on she is murdered for it. As a favor to her father Barnaby looks into the case.
Barnaby investigates a woman who has set out to exact vengeance on the two men she blames for her fathers suicide. After killing the first one she is double crossed by the second one and her boyfriend in order to gain control of her assets.
An estranged sister and her boyfriend try to cash in by claiming to be the mother of her sister's daughter that she had given up for adoption 22 years ago- and who just happened to inherit millions of dollars. Barnaby investigates further when things don't add up.
A woman scorned hires Barnaby to find her polygamist husband so she can collect child support. But what Barnaby finds is an elaborate scheme to blackmail an attorney who is having an affair with the other wife of the philandering husband.
A wealthy art collector's much-younger wife ('Donna Mills' qv) plots to replace one of his paintings with a forgery, but her plan is complicated when he collapses and dies after catching her in the arms of her lover.
Ray Dixon has too much invested in molding his son Norm into an Olympic champion and sees those dreams threatened by a rival swimmer. Ray changes out his medication and the young man dies. Barnaby Jones tackles an seemingly unsolvable case.
The death of a woman's sister is ruled a suicide, but the woman doesn't buy it and hires Barnaby to look into it. What he discovers is a man who preys upon lonely single women for information so he can steal from their businesses that they work for, and he may have had something to do with the woman's death.
The brother of a man imprisoned for murder kidnaps and holds Betty hostage. In exchange for her release he demands that Barnaby finds enough evidence to clear his brother of the murder he did not commit.
A stable boy who's been in trouble with the law before is afraid that he's responsible for a horseback riding accident that resulted in the death of a wealthy business man. Barnaby investigates and believes that not is all as it appears.
When the owner of a restaurant is found dead, his brother whose also his partner asks Barnaby to investigate.And he thinks Barnaby should focus on one of his brother's employees whom Betty knows. It seems that the owner was always making passes at his wife. And another employee saw the two men fighting on the night the owner died and tries to blackmail them. But the wife has other plans.
A mentally challenged young man stumbles upon a murder being committed and tries to help the victim, but he's too late and the real assailant flees the scene before any other witnesses show up. The local sheriff wants to charge him for the murder, and it's up to Barnaby to prove that he has the wrong man.