After discovering their house burgled, the Harts find a hidden room---and learn the original architect/owner kept a fortune in bonds in that room, a fortune targeted by a young broker at the finance firm where the architect did business in his younger years.

When a playwright friend of the Harts' is killed and the Harts' copy of his last work is snatched, Jonathan is convinced something in the play motivated the murderer.

Jennifer suffers a concussion in a fall at the park, meaning no one but Jonathan believes she witnessed a patient's murder in a small hospital where her debt ridden doctor is part of a scheme the FBI has been investigating several years.

After a young model is killed at a fashion party, Jennifer and Jonathan agree to pose for a fashion shoot that leads to another murder. But Jennifer may have been the intended victim.

The Harts' unscrupulous lawyer hires an assassin to eliminate Jonathan with plans to court and marry Jennifer and thus gain control of the sizeable estate.

To catch a group of counterfeiters who murdered an investigator, Jennifer and Jonathan go on a cruise, she posing as a European countess and he working as a ship's steward.

A scramble for a smuggled barbell highlights a health center opening attended by the Harts and several bodybuilders.

A used bullet hidden in their house by a new Hart employee leads to a cat-and-mouse evening with a murderer.

It's roundup time at the Harts' ranch, but Jonathan and Jennifer are distracted by dying animals, a rumored chemical spill orchestrated by a Texan hoping to strip mine valuable coal from the area, and a murder in which the local sheriff may be involved.

Hart Industries's industrious but slightly awkward chief accountant Stanley Friesen is set up to take a murder rap after an evening on the town. In an attempt to clear him, the Harts retrace his steps (and act as singles) which leads them to discover a gambling ring.

The Harts want to give their charity committee gourmet chocolate hearts as a thank-you, but when one turns out to have been part of a smuggling operation, can Jonathan and Jennifer figure out what is going on before someone tries the "special" chocolates from an unknown admirer?

Scalped stolen opera tickets land Jonathan in the middle of a plot to assassinate the DA who is fighting organized crime.

When Max's long dead ex-wife suddenly reappears, kidnapping and a hot diamond necklace are not far behind.

Jonathan and Jennifer are in Hawaii for a croquet tournament when a tournament official is stabbed, and the Harts wind up in an international dilemma involving the KGB, MI-6, the CIA, and a fancy key that may unlock deadly secrets.

An Egyptologist is killed just before the opening of a stagey exhibit, featuring the mummy of an ancient Egyptian prince who legend says is waiting for his princess to join him in death -- and she looks just like Jennifer.

Jennifer and Jonathan go undercover to identify a toy plan thief who has become a murderer.

Freeway is chosen to star in a new dog food ad campaign, but the creator has a secret ingredient and will kill to hide it.

Jennifer has a doppelganger, married to a man who let his old partners take the fall for a robbery. The doppelganger reluctantly agrees to help Jonathan after Jennifer is kidnapped by one of the partners demanding a share of the crime's proceeds.

After witnessing a young woman's murder unexpectedly through a telescope in his friend's business office, Jonathan stumbles trying to pursue and catch the killer but hits his head and loses his memory. As he tries to recover he suspects the dead woman may have been his own mistress---and that he might have killed her.

Vacationing in New York City, the Harts look forward to a nice lunch with Jennifer's friend and her new husband, but her husband suddenly disappears and is shortly found dead. Meanwhile, two men who followed him out of the restaurant next show up in his L.A. apartment and start following who they think is his wife: Jennifer.