In order to save Max's life, Jonathan and Jennifer join a criminal's (Patrick Macnee) elaborate scheme to steal $20 million in gems.
The debt-ridden brother of Max's pen pal (June Allyson) follows her on a trip to see Max, whom both he and she believe is wealthy.
The Harts' videotape of a skiing vacation sheds some light on a champion skier's death on the slopes.
Jonathan and Jennifer pose as a college professor and a student to prove Max's basketball-star nephew innocent of cocaine charges.
Jennifer's part in a commercial could be her swan song unless Jonathan can stop a deranged man who has rigged a camera to explode.
On the Greek island of Rhodes, the Harts become entangled in a smuggler's plan to steal ancient artifacts.
The Harts enlist skaters Tai Babilonia and Randy Gardner to assist an Olympic hopeful marked for murder.
The Harts encounter industrial espionage when they agree to care for a dog carrying an important biogenetic formula.
The Harts help Max search for his friend (Dorothy Lamour), missing after being victimized by con men.
The Harts' planned benefit performance in New York City is marred by a psychotic stage manager with designs on Jennifer.
Jonathan and Jennifer hide in a convent after she witnesses a gangland murder, but the killer finds them.
The Harts befriend a girl (Kari Michaelson) recently awakened from a seven-year coma caused by an incident that left her orphaned.
The theft of an ancient jade dog leads to Macao, where the Harts battle a superstitious arms dealer (Soon-Teck Oh).
A greedy relative of a deceased Scottish chieftain battles to succeed the late clan leader but must compete with Jennifer for the title.
Jennifer's father (Ray Milland) believes that a beautiful woman (Samantha Eggar) is Jennifer's sister, but Jonathan is not so sure.
While in Greece, the Harts learn of a scheming tycoon's plan to pull Hart Industries away from Jonathan.
A tennis pro romances wealthy clients and passes data from them to a crooked stockbroker; guest Martina Navratilova.
The Harts' probe of a philandering British husband leaves them playing the "fox" in a deadly hunt.
Jonathan agrees to test an experimental Navy aircraft, but doesn't know the manufacturer plans to destroy it.
Jennifer mediates between the police and ruthless jewel thieves when Jonathan is taken hostage during a Paris robbery.
A polo championship involves the Harts in a plot to smuggle a $1 million jewel; guests Rossano Brazzi, A Martinez.
Jonathan and Jennifer recall the danger that surrounded their first meeting; guests David Warner, Simon Jones.
Discovering that a health-club owner is lacing a diet drink with dangerous amphetamines could bring the Harts to an untimely end.
The Harts throw a party to expose a neighborhood art-theft ring.
A disturbed woman's (Mimi Rogers) meeting with Jonathan sparks an obsession that propels her to kill.
Jonathan pretends he's Max when an assassin (Julie Newmar) takes him hostage on her way to kill Hart.
The Harts must find vacationing Max after accidentally giving him a lethal cigar as a going-away gift.
A soap-opera actor plans to kill scriptwriter Jennifer when she must write his character out of the show.
While in the Bahamas, the Harts uncover a scheme to impersonate a famous recluse (Andrew Duggan); guest Bubba Smith.
A woman's (Diana Muldaur) plan to sell her husband's perfume firm to Jonathan leaves her a widow.
The death of a Hart Industries geologist in the Peruvian jungle leads to a plot to exploit a lost Inca treasure.
Freeway's nose helps when the Harts become unwitting possessors of $500,000 in cocaine.
The suspicious death of one of Jennifer's former students turns the Harts' getaway weekend into a murder investigation.
A big-game hunter plans a jungle revenge after Jonathan bests him in a major business deal; guests David McCallum, Tippi Hedren.
A jingle-gram company serves as a front for an organization of burglars targeting the Harts.
Jennifer, under cover to research an article on a health spa, uncovers murder and fraud when she finds a wealthy spa patron's body.
The Harts help a Middle East king recover his badge of office, a statue of a lion stolen by an adversary.
Max departs to enjoy the $1 million he won in a contest, but his greedy replacements have designs on Hart Industries.
Jennifer's posing as a gothic-romance writer entangles her in a reader's violent fantasies; guest Ray Walston.
The Harts consider investing in a mining town turned into a tourist spot but learn not all the bullets are fake.
A man who has coveted Jennifer since prep school plans to kill Jonathan during a class reunion.
A gambler entrusts Jennifer with a briefcase full of money, later switched for counterfeit; guest Simon MacCorkindale.
Jennifer's aunt (Eva Gabor) weds for the seventh time, but the groom dies while eating wedding cake.
Jonathan's efforts to buy his and Jennifer's honeymoon bed are twice thwarted by theft; guest Antoinette Bower.
A loser pretends Jennifer's car hit him, but his crooked lawyer raises the ante by later killing him.
Jennifer unknowingly acquires a rare coin and becomes the target of two men willing to murder for it.
The Harts attempt to retrieve a stolen $250,000 baseball-card collection and free the kidnapped owner.
The CIA asks Jonathan to pretend to be an agent to uncover an information leak.
At their mountain retreat, the Harts aid an innocent caretaker framed for murder by a local sheriff.
Greedy distributors put an expensive label on the Hart wineries table vintage.
The Harts' attempts to clear a friend (Andrew Prine) accused of killing his lover (Leigh Taylor-Young) lead into a fantasy world.
A jealous American ballet star frames his partner's lover, a defecting Soviet dancer, for murder; guest Clive Revill.
The Harts fake marital woes to discover who is attempting to break them up; guests Nicolas Coster, Louise Sorel.
The Harts travel to a French coastal island to meet a publisher, who vanishes that night.
Vacationing in Hawaii, Jennifer overhears a woman's plot to kill her husband, a wealthy businessman.
A beauty-salon operator hypnotizes Jennifer into stealing her friends' jewelry; guest David Hedison.
Jennifer learns her father (Ray Milland) is a former intelligence agent targeted for vengeance.
The Harts become the unwitting possessors of a priceless stamp and the targets of a desperate collector; guest William Daniels.
The Harts' test of a new underwater camera leads to murder and rumors of underwater treasure; guests Pat Hingle, Sandahl Bergman.
The Harts find murder and intrigue at the track as they prepare for their Thoroughbred's debut.
A stranger contaminates the Harts' pool, blinding Jonathan, then attacks him in the hospital.
Jennifer faces danger after she is lent a flashy outfit with "rhinestones" that are really diamonds.
An eccentric art collector (John Dehner) wants to add Jennifer to treasures by eliminating Jonathan.
Jonathan's look-alike and his magician brother (Harry Blackstone) plan to kill Jonathan and run Hart Industries.
Jonathan fears for Jennifer after the murders of friends who, like her, posed for a fake-fur ad.
On a train trip, the Harts investigate an undercover police officer's death; guest Carol Lynley.
A mishap in Acapulco finds the Harts posing as servants to prevent a murder; guest René Enríquez.
Jennifer is one of four finalists in a prestigious rose competition and also the next chosen victim of a judge intent on murder.
Jonathan and Jennifer's home is ransacked by a stockbroker looking for the secret passage to a forgotten fortune in lost bonds.
Jennifer's involvement in a theater group could prove deadly when the director (Anthony Newley) uses murder to conceal a deception.
Hospitalized Jennifer witnesses another patient's murder and is pursued by the killer after being released; guest Jared Martin.
The Harts' lawyer methodically plots to eliminate Jonathan, seize control of Hart Industries' funds and take possession of Jennifer.
Jonathan poses as a steward and Jennifer as a countess when they embark on a gambling ship to crack a counterfeiting ring.
A scramble for a smuggled barbell highlights a health-center opening attended by the Harts and several bodybuilders.
The Royal Canadian Mounties come to the rescue when a killer aiming to destroy evidence holds the Harts.
The Harts are the next target of a ruthless tycoon who ruins ranchers by poisoning livestock; guest Jane Withers.
Jonathan and Jennifer pose as swinging singles to infiltrate a bar used as a gambling front; guests Joanna Cassidy, Amy Madigan.
Jennifer places a Valentine candy order with Mrs. Bittersweet, unaware the shop proprietor dabbles in murder and espionage.
Jonathan volunteers to be a decoy for police after he inadvertently receives a hit man's fee and a telephone number.
Max's ex-wife involves him in an escapade of a stolen diamond necklace, insurance investigator, extortion and murder.
After murder interrupts their Hawaiian croquet game, Jonathan and Jennifer postpone vacation plans for intrigue; guest Dolph Sweet.
A recent corpse in an Egyptian prince's tomb and a mummy at the window involve the Harts in a murder; guest Thaao Penghlis.
Jonathan and Jennifer go under cover in a toy-making division of Hart Industries to solve a case of murder and industrial espionage.
Freeway's wolfing of dog food for a commercial makes his masters question the ingredients.
Jonathan feeds information to a disreputable reporter to save Jennifer from abductors who mistook her for a look-alike.
A desperate killer hunts witness Jonathan, suffering from temporary amnesia.
A bridegroom's sudden departure leads to a case of missing money and murder; guest John Gavin.
Jonathan and Jennifer set out to help a wealthy businessman save his marriage and find murder instead.
When a French-cooking demonstration results in murder, the Harts race a shady investor to recover a priceless recipe.
The Harts probe a rash of jewel thefts on the Hart Industries cruise line; guest John Hillerman.
The owner of several Beverly Hills beauty salons joins with a racketeer to blackmail wealthy patrons.
The Harts' participation in an ESP experiment draws them into a bizarre murder involving twins separated at birth.
The Harts go to South America to exchange a diamond necklace for two kidnapped scientists, then recover their loss.
At a ski resort, Jennifer overhears a man and his mistress plot the death of the wife.
Freeway brings home a murder weapon that involves the Harts with a glamorous ex-convict and a jewel robbery.
A guest participating in a treasure hunt in a haunted house turns up dead.
The probe of a campus heroin ring ensnares Jonathan in a fencing duel with a college champion; guest Jameson Parker.
Jennifer plans to surprise Jonathan with her portrait, until the artist is found slain.
A gold statue of Buddha leads to a world of Asian intrigue and pursuing gangsters; guest Edward Mulhare.
A murder at the Hart laboratories uncovers a scientist manufacturing a powerful narcotic.
A new romance leaves Max framed for murder and the Harts in a deadly trap; guest Daniel J. Travanti.
Jennifer's article on prostitution opens a maze of corruption and murder; guest Markie Post.
Jonathan and Jennifer try to prove the innocence of friends implicated in a noted divorce lawyer's murder; guest Bonnie Bartlett.
A disturbed employee (Kathleen Lloyd) obsessed with Jonathan plots to kill Jennifer.
The Harts' purchase of an antique auto leaves them open to a wealthy couple's efforts to acquire the car; guest Murray Matheson.
Introducing himself as Jonathan Hart Jr., a boy charms the Harts and Max as part of an elaborate hoax; guest Dee Wallace.
While vacationing on their yacht in Mexico, the Harts answer a friend's call for help and find themselves jailed for drug dealing.
Jonathan intervenes when Jennifer's hospitality toward an author (Craig Wasson) results in her having a number of serious accidents.
The Harts join a health spa to find the truth behind a friend's death; guest Roddy McDowall. Story by Sidney Sheldon.
Einer von Jonathans Angestellten stirbt überraschend. Bei der Testamentseröffnung kommt heraus, dass Jack hoch verschuldet war. Dessen Sohn Jess zeigt Jonathan eine Baseballkartensammlung, die er geerbt hat. Die Sammlung ist ein Vermögen wert.
Jennifer Hart leiht sich von einer bekannten Countrysängerin ein Kleid. Das Prunkstück ist von oben bis unten mit Glasperlen besetzt. Sie weiß natürlich nicht, dass es sich dabei nicht um Imitate, sondern um echte Diamanten aus einem Raub handelt.
Jonathan Hart entgeht nur knapp einem Sprengstoffattentat. Es war nicht der erste und auch nicht der letzte Anschlag auf sein Wohlbefinden. Jemand trachtet Jonathan nach dem Leben.