When Thomas Magnum's childhood friend and Naval comrade, Dan Cook, turns up dead, Magnum is adamant that the official cause of death, a burst bag of smuggled cocaine, is bogus. He enlists the aid of Dan's sister, Alice, in taking on the Navy to uncover the true nature of the top-secret assignment Dan was working on before his death.
When Thomas Magnum's childhood friend and Naval comrade, Dan Cook, turns up dead, Magnum is adamant that the official cause of death, a burst bag of smuggled cocaine, is bogus. He enlists the aid of Dan's sister, Alice, in taking on the Navy to uncover the true nature of the top-secret assignment Dan was working on before his death.
Magnum is hired by a beautiful Chinese antiques dealer that he's making a play for, to protect a precious ancient vase, The Soul of Sung, until it's buyer arrives in Hawaii to collect it. But unbeknown to him, the priceless ornament is wanted by a Tong gang from the girl's home country, and a deadly martial arts assassin who can kill in the blink of an eye is hot on the trail.
It's the Christmas season, and against his better judgment, Magnum agrees to being hired by five young schoolgirls to find their teacher, who has seemingly gone missing after falling in love. While he's working on the case, Magnum manages to convince Higgins to let the young girls stay on the Masters' estate, but he's unaware that he's being deceived in a scam over a valuable painting recently purchased by Robin Masters.
Magnum returns from a case to find that Higgins' old Army commander is staying on the Masters' estate, under tight security, until some I.R.A. members he helped capture are tried. Two secret intelligence agents hire Magnum to protect the brigadier and foil assassins out to kill him before the terrorists' trial, but the "need to know" basis the Agents insist on operating by only serves to complicate matters for Magnum.
When a beautiful model-actress is killed by a shotgun blast in a scenario closely resembling a scene from the script of an upcoming film, it is seemingly suicide. Magnum is hired by her former producer and lover to investigate any other men that she may have been seeing before her death -- a case that Magnum is reluctant to take, but, feeling guilty for not taking it before the girl was killed, he agrees. But as the investigations unfold, it becomes apparent that there is much more to the case than first appears, and the supposedly murdered woman was being hounded by the obsessive former lover. The case reaches it's pinnacle when Magnum, still haunted by nightmares of the Vietnam war in his dreams, finds himself reliving it in much more reality, in a deadly hunt down on a deserted tropical island.
When Saul and Lena, an aging couple who run a local shop, abruptly make plans to leave town, suspicious Magnum and Rick, who are friends with the couple, investigate – only to arrive at the pair's home to see Saul whisked away in an ambulance after suffering a heart attack. Yet when they check at the hospital, he's not there. It becomes apparent that Saul has been kidnapped, and as Magnum houses Lena at Robin's Nest while looking for her missing husband, she explains that they are Holocaust survivors, who are being hunted by neo-Nazis. But there's a twist that Magnum doesn't foresee.
Higgins volunteers Magnum's services to guard a wealthy socialite's quarantined dog, after the attempted dognapping of the canine. Sir Algernon Farnsworth soon finds himself to be the most wanted dog in Hawaii, when his former owner, aging gangster Victor DiGiorgio, needs to get him back. Magnum and an animal regulations officer are soon on the run with Algie from the would-be dognappers -- and the fact that the officer seems to be scared of dogs doesn't exactly make matters any easier - but just why does DiGiorgio want the mutt back so badly?
A new singer at the King Kamehameha Club who claims to have E.S.P. hires Magnum to find her childhood friend-come-fiancée Eric, a Marine who has been listed as Missing In Action since 1972, whom now she has started getting psychic visions of. As he investigates, Magnum discovers that Eric was a member of the top-secret 'Delta Section', and is refusing to come in from the cold until he exposes the division's activities to the press – but is being pursued by a Delta operative who is determined to bring Eric in and keep him quiet, at any cost.
Magnum is hired by a Supreme Court nominee to find the woman he married forty years ago, in 1941, on the eve of the raid on Pearl Harbor. He was a young Navy Ensign, she was a prostitute, and after their marriage they subsequently became separated in the bombings, with the Judge presuming her dead - until recently, after he has started receiving blackmail threats relating to an incident forty years ago. Magnum's investigations into the case are helped by the fact that Higgins wants a favor, and is being overly nice and co-operative in return.
Rick is organising a surf-ski competition to be held at the King Kamehameha Club (much to the disapproval of co-committee member Higgins) when a Kahuna appears a places a "curse" on the club and all who use it. Magnum and others are sceptical, but the native locals take such curses very seriously, and it seems there may be something in it when one of the competition competitors suddenly collapses and dies; then, amongst other incidents, fire breaks out in the kitchen; and when Rick falls ill. Magnum investigates to try and find if there is a more logical explanation behind the events, but his enquiries aren't helped by a hounding news reporter, who sees the series of strange incidents as a chance for a big news story.
T.C. makes a late-night flight to land on a tanker, but on the journey back he is cornered and arrested by the Coast Guard for transporting drugs. Magnum and Rick are certain of their friend's innocence, but are shocked when he intends to accept the charges and refuses their help. Magnum investigates to find that T.C.'s trip to the tanker was to collect and bring home a man who once saved T.C.'s life in Vietnam, a deserter who is now a supposedly a reformed drug addict, and who was calling in an old debt to be flown back into U.S. territory.
A bubbly young woman hires Magnum to find her father who, after being missing for over ten years, had send her a postcard from Hawaii. But her father is involved in some rather shady business, and Magnum isn't the only one looking for him.
A perky woman hires Magnum to protect 'Norman', who is facing kidnap unless she pays a ransom; but the case has some unexpected turns when Magnum finds that her uncle is an old Vietnam comrade who is against him being hired, and that Norman is none other than a prized race-horse.
An elderly, blind friend of Magnum, Agatha Kimball, hires him to help payoff her granddaughter's blackmailer who says he has damaging information against her, but asks him to end the investigation there. But when Agatha is the victim of a few too many "accidents," Tom digs deeper into finding out what this is all about.
Magnum has been hired by a woman to act out some of her rich, bored sister's fantasy dramas, concocted from 1930s Dashiell Hammett films. Although growing to enjoy the world of fantasy, Magnum has a hard time keeping up with the eccentric woman, and when he finds out that her husband is a wealthy, infamously jealous and bad-tempered business man, he decides to cut his loses and end the arrangement. But he is just informing the girl that he is calling a halt to his participation, when they are attacked by real thugs, and soon after the girl is poisoned. With the woman still caught up in her world of fantasy, Magnum must thrust himself back into reality to find out just what is really going on.
Magnum tries to impress a beautiful "fan" of Robin's that he befriends, by showing her the Robin Masters estate, only to learn that she is actually a top security expect hired by Robin to test the estate's security. The security company she works for has been hired after Robin's life is threatened if he publishes his latest manuscript; and with him heading for one of three possible locations to collect some dictation tapes, she asks Magnum's co-operation in seeing that the estate is on top security in case it is the destination he's heading for. With the additional aid of T.C. and Rick, Robin's Nest is soon turned into a heavily guarded fortress, but there are parties out trying to see that Robin never makes it to his destination.
Magnum is hired by a fitness trainer for only one day in hopes of finding her missing fiance. But to everyones surprise, he is not the only one searching for the man. Tom is also challenged by T.C. to enter an Ironman competition.
Magnum is hired by Billy Joe Bob, when his sister Carol Ann is discovered to be missing. Short tempered Billy Joe Bob, isn't helping matters by beating up suspects while on a search for his sibling who apparently is mixed up with the wrong kind of people.
When an archaeologist's boat is spotted in the Nihoa Channel, Magnum is hired by his daughter to locate him. Tom takes on the case despite the warnings from the locals that the Channel is cursed by evil spirits.
Rick meets a beautiful woman, Sara, while walking on the beach one evening. Suddenly the woman disappears in thin air. Rick asks Magnum to help investigate the strange occurrence from that night. His findings are even stranger when he learns that the woman had died 35 years ago on the beach after committing suicide. Now he wonders if someone is trying to impersonate Sara, or is there another explanation to her mysterious vanishing.
A defector from the Soviet Union has asked Magnum to help his girlfriend, a lovely athlete follow in his footsteps. But this will be a tough assignment since the KGB has a tight watch on their athletes.
Magnum spots a woman which he believes is a Michelle, who he married and thought was killed in a bombing in Vietnam. Although he coworkers think he is mistaken, Tom goes on a search which leads him into an uncomfortable political web.
Magnum's search for Michelle is interrupted when he is called up by the Navy to testify in Washington, a ploy he believes to keep him from finding his lost wife. But a quick reuniting with Michelle reveals that she is married to a Vietnamese General who is in charge of returning POW's and MIA's from Vietnam, and that she is wanted as a traitor spy.
The relationship between Higgins and Magnum becomes strained when Tom is convinced that a woman who is more interested in Higgins than in him must be using him for a reason.
Magnum investigates the death of a friend, a former surfing champion who was found on the beach. Tom has a reason to believe that the two prime suspects, a Vietnam veteran and a drug pusher are not the man he is searching for.
Mad Buck Gibson, a thrill seeking author is the subject of Magnum's newest case as his ex-wife asks him to keep watch over Buck until she can get her alimony she is owed. but Tom discovers that he may have a deep dark secret behind his destructive behavior.
Magnum is asked by the wife of an old Navy buddy to help her after he is kidnapped and held for ransom. Her plan is to have Tom make the money drop without her father gaining knowledge of the incident, knowing he was never happy with the marriage. But Magnum becomes suspicious as he delves deeper into the facts.
Magnum is asked to help protect the life of a prima ballerina, after a number of attempts are made on her life. Although the two can not stand each other, they soon find themselves romantically involved.
The autobiography of an eccentric millionaire, Harold Farber, is being ghost written by a beautiful woman who needs Magnum's help when her research material is stolen by someone intent on making sure the book never sees the light of day.
Magnum is asked to help find a international assassin by an old friend from the guy's Vietnam days, journalist Kate Sullivan. His investigation reveals the target as being a Prime Minister from a small island republic. But Tom is second guessing Kate's importance over getting this story.
While working on a computer espionage case for a company, its president asks Magnum to find out if his wife is having an affair behind his back. His findings creates a problem when he discovers that she is cheating on her husband, with Rick.
Magnum awakens to find himself in the hospital suffering from amnesia. His only memory was that he was working on a missing persons case. But when his cap is found near the woman's dead body, he is named as the prime suspect.
When a beautiful woman is found to have been kidnapped by the mob, Robin asks Magnum to go to Sicily and rescue her from their clutches. But a love affair between Tom and the woman and the mob arrive on the island to bring her back, trouble is sure to ensue.
Magnum is asked to join a football team undercover by an old Naval friend who is now a pro quarterback, and is being targeted for murder. Now, if Tom can just survive the training camp.
Magnum is hired as a bodyguard for Jeannie "Texas Lightning" Lowry, a card shark who is attending a high-stakes poker game aboard a luxurious yacht. But Tom soon finds out that Jeannie was there for another reason and they would need to make an escape, which leaves their tormentors believing they had died.
Magnum is hired as a stunt double for a movie when Robin's property is chosen for the location of a film starring Olivia Ross and her husband Jack Martin. Tom is forced into an investigation when a stunt gun shot off by Olivia fires a real bullet into her husband.
Magnum is hired to find the missing girlfriend of a Vietnam veteran, but soon finds out that his real intention was to work out a payback against Tom.
Magnum is asked by the daughter of Higgin's illegitimate half brother Elmo Ziller, who was assumed dead, to protect him from killers and prove that it is Ziller's wife who is behind the plot.
Magnum is asked to step in and investigate whether one of the partners for a fashion designer is responsible for the death of one of her other partners. But the deeper he probes, the more he believes that another murder is in the works.
T.C. is warned by an old friend from his Vietnam War days that they are being pursed by the Colonel from the P.O.W. camp in which they were once held. Although TC believes that his friend is hallucinating, he soon finds himself and Magnum running for their lives.
Colonel Greene and Admiral Hawkes question the death of Mac and are concerned with Colonel Ivan, who is intent on killing Magnum, T.C. and Nuzo. But then a discovery is made about Nuzo, which puts T.C. and a Japanese prince in danger among others.
Magnum is put in charge of protecting some priceless antiques as he mingles with high society. But Rick and A.J. Simon, P.I.'s themselves, are hired to retrieve an ancient and cursed Hawaiian artifact.
A box of books in which Magnum brings back from the docks has a Japanese stowaway inside.
T.C.'s helicopter is hijacked by a pair of thugs who were portraying tourists, and is forced to bring them to the prison to help escape after a break out.
A deadly African virus forces Magnum and Higgins to be quarantined together...but is this the real reason why?
In a fantasy episode, Magnum finds himself in the year 1936 and forced to help clear a union leader of a murder rap.
Higgins is accused of murder when his old boarding school roommate and nemesis is found dead, causing Magnum to investigate to what really happened.
Magnum is asked by a former boxing champion to find his missing son, but the facts don't add up for Tom.
Magnum is made a body guard for a young tennis star with a bad reputation, who has received death threats. What Tom didn't expect was to meet up with a long lost friend, and that friend would be the prime suspect for the threats.
Magnum investigates why a woman is denied permission to scatter her fathers ashes into Pearl harbor, revealing an old court martial case.
A former Vietnam nurse, now a doctor, is accused of killing three patients in which she was taking care of.
Magnum is surprised when he discovers that he was named an heir to the estate of a practical joker, who was recently killed in a plane explosion. But it looks as if the killer is now aiming for the heir.
When a valuable Kenzan artifact is stolen from a Samurai warrior by a Ninja, Magnum delves deep into the world of ancient Japanese culture.
While working as volunteer junior basketball coaches, Magnum and T.C. discover that their newest player is living in a foster home run by criminals.
Magnum uncovers a plot by Robin Master's former mentor to commit murder while in town to interview a reclusive bird expert.
Magnum goes undercover as the husband of a CEO's niece in order to catch a thief within a family owned business.
Magnum investigates when a Ferrari in which Higgins was driving had it's breaks tampered with.
Magnum partners up will an attractive young woman to investigate the death of a lifeguard who died shortly after being seen driving a car which was far above his means financially.
Magnum is linked between his past, a plane accident and drug dealers after having just met a pilot who seemed familiar to him.
When an encyclopedia salesman who was just sprung from prison receives threats from a corrupt parole officer, Magnum wants to be sure he is caught and sent to prison himself.
Robin Masters is throwing an Spring equinox party in which is interrupted by a storm, a guest which has gone into labor and uninvited guests in the form of a pair of escaped convicts.
Magnum has his hands full as he is hired to investigate whether a wife is cheating on her husband, then meets Higgins' half brother, a Northern Ireland priest who believes an English relic was stolen during a weapons search for the I.R.A.
Magnum's surf ski capsizes and he gets trapped in a fast-moving ocean current. Rick and T. C. race to find him before he collapses from exhaustion and drowns.
For the first of several times, Magnum teams up with St. Louis private eye Luther Gillis. This time it's a kidnapping case.
Rick gets into a full-blown jam when a childhood buddy asks him to investigate an insurance claim for a priceless figurine.
Rick asks Magnum to chaperone his visiting sister. She ends up murdered in an alley.
Magnum pursues the perpetrator of a series of convenience store robberies while Higgins organizes a charity bingo game to help two elderly sisters about to be evicted from their residence.
Higgins falls for a damsel in distress but she thinks Magnum has the hots for her. Both men spring into action when she gets kidnapped.
A bet between Robin Masters and a slimy magazine publisher could leave Magnum and Higgins out on the streets unless Magnum's softball team can emerge victorious in a contest against the publisher's team of ringers.
Higgins hurriedly summons Magnum back from a job in Detroit when T.C. foolishly decides to step into the boxing ring.
Beth Davenport lookalike Holly Hudson, a former Saigon D.J. during the Vietman War, hires Magnum to find her missing fiancee.
On Christmas Eve, Magnum and the gang find themselves stranded on a small island which is scheduled to be used by the Navy for gunnery practice.
A Little League tournament contains a Crown Prince as a participant. He plays centerfield for his nation's team. Magnum then discovers an assassination plot against the boy.
After a costume ball on the estate at which some valuable jewels go missing, Higgins finds himself the leadins suspect in the murder of one of the party guests.
Magnum and company are recruited by Carol Baldwin to be part of an undercover sting operation against a drug dealer.
Magnum and a bank teller get themselves locked inside a bank vault where they discover counterfeit bills.
T. C. reunites with an old jazz singer galpal whom he once loved in Vietnam. Unfortunately, some bad dudes from Detroit are on her trail.
Magnum has to team up with St. Louis private eye Luther Gillis once again when Higgins and Luther's secretary/galpal go missing.
Magnum becomes involved with a damsel whose brother disappeared under mysterious circumstances. Meanwhile, Higgins tries to produce a version of The Mikado for a visiting dignitary.
An old pal of Higgins arrives in Hawaii thinking he's Sherlock Holmes involved hot and heavy on a case. To watch out for his old friend, HIggins has no choice but to play Dr. Watson.
Hot and heavy on a case, Magnum keeps running into a damsel and wonders whether these run-ins are a little too coincidental.
A former client of Magnum's hires him again when she and her daughter have a run-in with some nasty surfer dudes.
Three eyewitnesses tell conflicting stories about a robbery attempt forcing Magnum to piece things together before the thieves strike again.
Magnum finds himself falling for a sexy woman who's identical twin sister claims that she's a raving psychotic with a history of attempted murder.
Magnum tries to get at the truth about a beautiful woman for whom he's fallen and gets himself into a full blown jam.
Depressed over the suicide of his galpal, Magnum imagines that he sees old pal Jerry McReynolds on the streets of Honolulu but Jerry died two years ago. Is it a hallucination or has Magnum's old friend returned from the grave?
Magnum tries to help a notorious bank robber find his hidden loot so that he can pay the ransom for his kidnapped grandson.
Magnum searches for pal T. C. whose helicopter disappeared during the course of a mysterious delivery.
A psychic begins having visions of her own murder and asks Magnum for protection.
Carol Baldwin approaches Magnum and asks him to look into the murder of a young mother. He finds out that things aren't quite what they seem with one of the suspects in the case.
Magnum is recruited to teach a class on criminal investigation to students at a local community college and soon finds himself, along with his students, involved in a murder investigation.
A Vietnamese boy hires Magnum to find his missing G.I. father.
Magnum once again brings in Luther Gillis to help him with a case that could have dire repercussions for both Higgins and Robin Masters.
Magnum is forced to let a mystery novelist tag along during his investigation of insurance fraud.
A famous jewel collection is being displayed on the estate and Magnum discovers that the security expert supposedly assigned to protect it is in reality the daughter of a notorious jewel thief.
Higgins plays Pygmalion for his punk rock cousin while Magnum investigates a shady investment scheme.
Higgins is paid a visit by some former school chums who mistakenly think that he owns the Masters' estate.
Magnum, T.C., and Rick head back to Southeast Asia to find an old war buddy who disappeared in Cambodia.
Magnum, T.C., and Rick try to help an old Vietnam War buddy escape captivity in Cambodia.
Con man Mac Bonnick slickers Rick when he sells him a luxury yacht complete with four beautiful geisha girls. Then the boat's true owners want it back.
A woman hires Magnum to track down five missing songs that a country singer wrote shortly before his death in a plane crash.
Magnum is hired by a rude Hall of Records clerk to find her missing husband.
A famous French detective gets Magnum involved in a mother of a case involving fraud and multiple identities.
Magnum and a rabbi team up to search for a priceless stolen Torah.
Magnum goes undercover as a convict in order to ferret out information regarding a missing 17 year old girl.
Robin Masters has purchased a new residence in England, a castle he has dubbed Robin's Keep. Higgins trains the keep's new steward, Ian MacKerras, while Magnum takes advantage of an opportunity to meet with an old friend from Vietnam, Geoffrey St. Clare. Arriving, Magnum discovers that Geoffrey has died in a automobile accident, but also discovers enough curious facts to warrant further investigation...
Magnum and his friend's wife Penelope investigate Geoffrey's death. Magnum recalls an earlier dream that seemed to predict his friend's death. He also grows closer to his friend's wife. But when Magnum finally discovers why Geoffrey was killed, it may change his view of his old friend. Meanwhile, Higgins has an opportunity to visit his own family - an opportunity he forgoes, which puzzles Magnum.
Magnum has a chance run-in with old high school friend Goldie Morris. She was then and remains now a political activist. Magnum soon learns she and some friends are the thieves who stole a trained dolphin from a local sea park. She thought the plan was to set the creature free, but her companions have different plans for the animal...
While watching a storm driven by the Kona Winds, Magnum sees a woman apparently fall into the ocean. He rescues her and brings her to Robin's Nest. There he learns that she saw her husband murder his business partner, and fears she's next. Magnum begins to investigate her husband - and to fall in love with her...
Magnum leaves Robin's Nest and goes to work for a hotel, the Hawaiian Gardens. He immediately alienates his new boss, chiefly by failing to catch an elusive thief. He'd better catch the thief, and quickly: an international jewelers' convention will soon meet there, an event sure to draw the thief!
Ron Pennington dies when he interrupts a grocery store hold-up. That's bad news for the robbers, because Ron was a good friend of T.C. and Magnum, who determine to identify the men and solve the murder. All they have to go on is a fleeting glimpse T.C. caught of the robbers. T.C. also tries to reach out to Ron's teenage son.
Magnum returns home for the funeral of his grandfather Everett, and re-opens some old wounds when he accuses his stepfather of stealing and selling a letter from Abraham Lincoln that has been in the family for generations.
The owner of a ranch on Hawaii calls on Magnum to put a stop to cattle thieves who will soon force him into bankruptcy. But the man he implicates is a business partner of Robin Masters, which could make things dicey for Magnum. On top of that, Magnum's employer hasn't been entirely honest with him...
Robin Masters's publishers organize a treasure hunt. To win a million dollars, readers will have to decipher clues in Masters's latest novel to deduce the location of the prize. Magnum, hired as a bodyguard by the woman overseeing the treasure hunt finds himself on the wrong end of a gun because some people will go to any length to win.
Admiral Hawkes calls Magnum back to Naval Service. The Admiral wants him to identify the source of a security leak in the coded communication chain. If Magnum cannot discover the link in three days, several vital documents will fall into the wrong hands. Complicating things is the discovery of incriminating classified data in Magnum's own car, a clear suggestion that he's "getting too close" but also not something the brass can ignore...
While diving, Magnum sees a young boy appear out of nowhere and gesture to him. Higgins, T.C. and Rick are skeptical, but Magnum eventually learns that the person he saw matches the description of a young boy who died in an explosion at sea years earlier. Magnum digs into the matter, convinced his vision was a plea from somewhere, imploring him to find the cause of the boy's death.
Higgins's friend Inky Gilbert brings a traveling carnival to Hawaii. Soon after it arrives, someone knifes a performer to death. Higgins asks Magnum to look into it, so Magnum and Rick go undercover, where Magnum discovers the stabbing is only the latest in a series of misfortunes to afflict the show. He must discover who is trying to force the show out of business, and why.
Robin sends his nephew R.J., who has failed out of several schools, to Higgins, hoping he can do something with the boy. Magnum's exploits impress the boy, who causes still more trouble: he impersonates his new hero, takes on a highly dangerous case and manages to get Magnum marked for death!
Robin Masters discovers that Higgins has been stealing cash and rare art pieces! Magnum must cope with the replacement Masters hires, at the same time investigating Higgins's departure.
Robin Masters purchased a wooden statuette of Amakua, which he plans to donate to a museum. After one attempt to steal it, he assigns Magnum the task of guarding it while it is on display on a cruise ship, en route to the museum. Magnum, in turn, enlists his friends T. C. and Rick.
Rick's boat is found, deserted. Magnum embarks on a search to learn what happened to his friend, efforts complicated by a zealous police detective named Katsumoto. Digging around, the men soon uncover evidence of mobsters and counterfeiting.
Magnum takes a case presented by Dan Wolf, a milquetoast insurance salesman who wishes to locate the father he has not seen in thirty years, a wealthy businessman named Theo Wolf. This proves a fatal mistake for one of the Wolf clan, and nearly fatal for Magnum.
Wealthy Lydia McCarthy hires Magnum to locate her family's former chauffeur and recover some jewelry she claims the man stole. But when Magnum finds the man, he claims his former employer is obsessed. That leads Magnum to probe further, and he uncovers a kidnapping ring that specializes in infants.
Higgins prepares to host a chess tournament. One important guest is Manuel Ibenez, the President of Costa del Rosa, whose life someone has threatened. Magnum investigates to find out who has made these threats, and discovers one suspect, Don Luis Mongueo, has a connection to Higgins and Ibenez...
Magnum and T. C. strive to save a clubhouse for underprivileged children from a greedy developer, while elsewhere Rick wins a million dollars and managed to buy himself only trouble with it.
Photographer Sally Faraday meets Magnum by accident - literally. She hits his car while being pursued by two men who want to recover certain photographs she took for a new book. She's not sure why; Magnum assumes she inadvertently recorded something someone will kill to keep secret.
Robin sends Magnum to Los Angeles to deliver lawsuit papers to a small company there. On the trip, he befriends a stand-up comedienne whom someone later murders. Magnum determines to solve the crime, and gets some help from an unexpected quarter, an attorney named Cynthia Farrell. Back on Hawaii, one of T. C.'s baseball players gets mixed up with car thieves and witnesses a murder.
Magnum and Cynthia become closer as they continue their search for the killer. Back on the island, T. C. also searches for the missing Kenny, whom he must find before a murderer does!
Carol persuades Magnum to guard a young woman, a deaf painter who witnessed a robbery and four murders. After she identifies one of the men from a police line-up, her life is in danger.
Recovering from an ankle injury, Magnum chances across Leslie Emory. A prostitute during his time as a hotel detective, she's a former prostitute now. And, she wants to hire Magnum to locate her sister Patty, who is still a prostitute. Magnum soon learns the missing woman is connected to some fairly powerful individuals...
Magnum is set to receive an award at a convention collecting private detectives when one of them, Jean Fornier, drops dead of poison. Magnum hunts for Fornier's murderer, with help from some of the other detectives, and eventually uncovers the gang of drug smugglers Fornier was hunting.
Magnum is preparing for his upcoming tax audit - alone - when someone with a lot of information about Magnum's past begins calling. The caller offers Magnum riddles based on nursery rhymes. Magnum dismisses him as a crank until he learns of a murder that matches the clues - and the mysterious caller offers more riddles, suggesting more killings...
When assassins come to kill General Hue, his frantic wife Michelle leaves her daughter with her ex-husband - Magnum - for safe keeping. As he watches the child, questions enter his mind, and he sets out to find his ex-wife and the answers.
An escalating war of jokes becomes increasingly mean-spirited, all touched off by Magnum's inadvertent erasure of part of Higgins's memoirs. In the midst of the trouble this causes him, Magnum is trying to gather evidence against a crooked gambling ring. Higgins and Magnum ultimately end up trapped in the elevator of a building about to be demolished, where Magnum accuses Higgins of being Robin Masters.
An editor friend of Robin Masters, Pamela Bates, visits the estate. En route, sometime tries to run them off the road! Magnum is set to look into it, but Pamela has an expert of her own on tap - mystery novelist and sometime sleuth Jessica Fletcher! But Magnum just can't leave it alone, which interferes with his current side project, a property investment with T. C. and Rick.
Magnum sees a native Hawaiian girl witness a murder. When the gunman goes after her, Magnum intervenes and both escape into the sea. The gunman shoots Magnum, who loses consciousness. When he awakens a few days later on the secluded island of Kapu, he remembers little about the incident - and it seems the island's residents don't want to help him learn any more. But the gunman and the girl are still out there somewhere...
T. C.'s children come to visit him in Hawaii. But his daughter Melody disappears at the airport, and then he learns the ransom will be $300,000. Magnum tries to discover who kidnapped the child, while Rick and Higgins help T. C. raise the ransom - an operation that includes selling the helicopter that is his livelihood. And Magnum discovers that this is tied to T. C.'s past...
Carol asks Magnum to observe a court case she'll present before her mentor, Judge Hannibal Kearns. He dismisses the case on a technicality, something he has done several times recently. Carol must face the possibility that her old mentor has accepted bribes, and asks Magnum to investigate. He turns up evidence that Ice Pick might be involved...
Higgins joins an expedition designed to raise the self-esteem of a group of young convicts. He'll lend it his survival skills, but when an escape goes badly pear shaped, he'll have to rely on his skills to keep himself alive. In his absence, Magnum, T. C. and Rick plan a party at Robin's Nest.
In 1941 San Francisco, private investigator Thomas Magnum investigates the murder of William Maxfield, a newspaper mogul whose rags to riches story might conceal old enemies. This story borrows from film noir, and features an array of characters who resemble modern Magnum's friends.
As T. C. gives Magnum a flying lesson, someone shoots the veteran pilot. Subsequent events reveal that the shot was meant for Magnum; someone impersonated him and tried to extort money from a Mexican gangster. And somehow, in the middle of all of it, is a man named Mac Bonnick.
Magnum's life has been better: he owes Rick money, he let some kids down and he got fired because he couldn't solve a case. So he decides a nice hike will clear his head. But on the climb, a centipede bites him, and then he gets his legs pinned under the wreckage of an antique fighter plane. The situation leads to introspection, and perhaps some answers.
Magnum's about to hit forty, and it looks like forty's going to hit back: while celebrating in Honolulu's Chinatown, he loses his Lucky Two. This $2 bill, given to him by his grandfather when he was thirteen, has been his lucky charm since. Searching for it, he gets drawn into a case of gunrunning, and nearly loses his life!
On the night of Sergeant Doheny's retirement dinner, vicious sexual predators raped and murder his granddaughter. He tracks them to Hawaii and enlists Magnum's help in finding them. When he finds one of the men, his relentless pursuit drives the man in front of a bus, fatally. When Doheny explains what happened to Magnum, he realizes the man intends to kill the other suspect, and determines to find the killer first, to spare Doheny a murder rap.
Lawyer Cynthia Farrell comes to visit Magnum, to see if there's anything to the relationship they started in Los Angeles. But he spends more time investigating a director of pornographic films on behalf of one of his actresses.
Magnum must jump through the hoops necessary to renew his investigator's license. While that goes on, he gets a welcome visit from his playwright aunt Phoebe, and the unwelcome news that the believes killers have trailed her to Hawaii from her native New York. Naturally Magnum has to do something about that.
Rick's friend Ice Pick hits the mattresses when he gets some information that his life's in danger. Then Rick's in hot water when the mechanic sent to kill Ice Pick turns up dead - and Rick won't even defend himself. That, of course, means that his friends must defend him...
Gunned down by a hitman, Magnum hangs between life and death. In that state, he visits those who mean the most to him, including his friend Mac, who died years earlier, to explain how much they meant. He must also help his ex-wife Michelle, but he's not sure how.
Friends and family try to help bring Magnum out of his coma.
While Magnum heals from his injuries, Higgins takes on his lifestyle right down to wearing Hawaiian shirts and driving fast cars, while Tom is laid back and dressing in a suit. Intrigued by Higgins sudden change Magnum checks out what is going on, discovering that he is seeing a woman who may be taking him for a pigeon.
Magnum and the wife of a waste management president have become an unlikely yet valuable teammate.
Magnum investigates the shooting death of his friend Lt. Tanaka, and uncovers that the man is also involved in illicit activities.
Magnum falls in love with a beautiful young woman while helping Higgins with a Hawaiian Historical Society pageant.
Magnum becomes entangled in Carol's personal and professional career when he moves in with her and her mother after she receives death threats.
Bank teller Susan Johnson takes a shot at Magnum during an investigation, having recently become a detective.
Magnum's ex-wife and daughter are in grave danger after Quang Ki is indictment is rescinded due to insufficient evidence.
T.C.'s troubled son puts Magnum's lucrative business deal on hold when he winds up in jail.
Higgins is in search for a priceless ancient scroll in which he believes had been created by an advanced culture.
Magnum receives some unwanted help from Luther Gillis, a St. Louis based detective when he assists Higgins in a search for Robin Masters' stolen manuscript.
Magnum receives a phone call from Hawaii while visiting his family in Virginia, which has him racing back to romance and danger and maybe even Robin Master's real identity.
Magnum continues his watch of Linda as she is stalked by a psychopathic killer. Meanwhile, as Rick's wedding looms, T.C. seeks to reconcile with his ex-wife, and Magnum finds out new which concerns his theory that Higgins is really Robin Masters, as well as Lily's true fate.