Jonathan and Jennifer enact a troubled marriage in very public places in an attempt to flush out the culprit who is trying to cause a rift between them.

Jennifer is stalked by a psychotic stage manager who lurks in the wings as the Harts don top hats and tails to perform in a charity benefit in the Big Apple.

A hitwoman is sent to kill a commissioner and ends up taking Jonathan, Jennifer and Max hostage.

Jennifer's cousin slips into a coma after being continually drugged by the owners of a health club.

A dying man gives Jonathan and Jennifer an ancient Buddha statue. The Harts are then thrown into intrigue and danger when they are pursued by Chinese henchmen and a diabolic giant.

The Harts are asked to ransom two scientist employed by Hart Industries when they are kidnapped in South America. When Jonathan, Jennifer, and Max, they wind up mounting a mid-night raid against the wealthy and powerful kidnapper.

A diamond ring given to Jennifer by Jonathan for their fifth anniversary enables their escape from a glass-walled room where they are being held captive.

Jonathan thunders into the glamour and excitement of polo, unaware that he and Jennifer have become targets for murder in a smuggling scheme using a prized polo mallet to transport a $1-million gem.

While in Greece, Jonathan and Jennifer race to save their lives and the future of Hart Industries when a European business magnate seeks to destroy them during a cross-country car rally.

Industrial espionage is a problem at Hartoy company. When the investigator Jonathan has hired is murdered, the Harts go undercover in an attempt to foil the crooks and save the company from financial destruction.

To strip mine the entire area, a ruthless mining tycoon is driving cattle ranchers out of business by poisoning the livestock via the stream that waters the properties. The Harts get involved when Jennifer's colt is poisoned.

Vince, a friend of Max's, arrives in USA to open a chain of health clubs. International criminals smuggle a solid gold barbell into the country with Vince's entourage.

Jonathan purchases their Honeymoom bed, but the wrong bed is delivered. In their search for the ""real"" bed, the Harts become entangled in an international art smuggling scheme through San Francisco and the Napa Valley.

Jennifer takes on a glamorous modeling assignment, not knowing that the camera is rigged with an explosive device, as Jonathan races to stop the deadly scheme concocted by a vengeful man from her past.

The Harts have a deadly encounter when they enter the mysterious world of psychic phenomena. A Hart Industies employee with amazing powers of ESP, a twin sister, and a wealthy grandfather, becomes the target of a deranged killer.

The Harts take a luxurious cruise on a Hart Industries liner to investigate a series of jewel thefts. They find themselves at the mercy of the jewel thieves' rival burglars.

The menu features murder when the Harts take a gourmet cooking class. The Harts vie with an unscrupulous financier for a recipe which might benefit the world.

Normally finicky, Freeway is quite fond of a new dog food and ends up in a dog food commercial. When the Harts have a party, some of Freeway's new food is mistakenly ingested by some guests who then behave as if drugged. Jennifer and Jonathan are in danger when they attempt to find out its secret formula.

During an Opening Night party for a new Egytian exhibit at the museum, the man who discovered the tomb is murdered. The Harts become involved in the investigation when Jennifer sees a mummy at their home

Jennifer orders three chocolate valentines. Someone makes a mistake and delivers the wrong heart for the Harts. One contains a smuggled object that the thieves want at any cost.

Max creates a rose hybrid he calls the Jennifer Hart Rose and enters it in a prestigious rose contest under Jennifer name. She becomes the target for murder when she is stalked by a psychotic leading judge.

The Harts become involved in international intrigue when they infiltrate a ballet company to clear a world-renown Soviet danseur of murder charges.

The Harts witness a murder when the spiritual mentor and bridegroom of Jennifer's aunt meets an untimely death.

While visiting a wildlife reserve, Jonathan and Jennifer are hunted as prey by a competitor of Hart Industries.

A young figure skater's dreams of Olympic gold will be shattered unless Hart Industries can mix modern technology with the astounding talent of skater Tai Babilonia.