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.

Jennifer, flying a kite in the park, falls and hits her head. She's hospitalized with a slight concussion. While in hospital, she witnesses the murder of another patient and tries to convince Jonathan of the strange crime is being covered up.

A psychotic man pours a blinding chemical into the Harts pool. Seconds after Jonathan dives in for his morning swim, he surfaces, screaming in pain.

Jonathan's new suit has been switched with another. To save time he decides to make the exchange himself rather than through the taylor. At the other man's hotel room, Jonathan and Jennifer discover a body.

Max is duped into thinking that he has won a million dollars and leaves the Harts to thieves who take over the house.

A young reporter influenced by Jennifer is murdered by her fiance's employer.

A psychotic woman is obsessed with Jonathan and is killing anyone who gets her way.

Jonathan and Jennifer remember how they first met and fell in love in the midst of murder and international intrigue in the picturesque locale of London.

A traditional fox hunt is marred by murder during the Harts visit to England -- and sends them off on the trail of a killer.

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.

The Harts lives are at stake when a valuable ancient jade carving leads them into the heart of mysterious Macao, where they encounter a Chinese arms dealer who has become a threat to U.S. national security.

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.

The Harts and Max fear for their lives when the debt-ridden brother of Max's penpal believes Max is rich and comes to steal some of his fortune.