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.
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.
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.
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.
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.