Thomas arrives in Los Angeles to deliver lawsuit papers to a small film company on behalf of Robin Masters, and during the trip befriends a stand-up comedienne. But when he finds her murdered in his hotel room, he investigates to find who is behind the killing. When he goes to deliver the subpoena to the film company, he strikes up a relationship with the attractive young attorney, and the pair work together to find the murderers... Meanwhile back in Hawaii, one of the players on T.C.'s baseball team is mixed up with some small time car thieves, who witnesses his friends being shot dead after stealing a car...

Conclusion of this feature-length / two-part story. Magnum and Cynthia became ever closer to each other as they investigate Marti's murder. Their search leads them to a drug trafficker, but their snooping around sees them almost killed. Back in Hawaii, T.C., with help from Rick and Higgins, continues to search for the missing Kenny, and get him out of the trouble he is in...

A gifted deaf painter is the only eye-witness to a bank robbery in which four people were slaughtered. Carol persuades Magnum to secure the young woman on the Masters Estate and act as her body-guard when her life is endangered after identifying one of the perpetrators in a Police line-up...

Thomas' luck takes a tumble when he injures his ankle while training for an upcoming charity sports event, and if his foot doesn't heal in time, his place will be taken for the race. But his luck looks set to fall even more when he finds that prostitute Leslie Emery, who he met when he was working as a hotel detective, has now given up working as a call-girl and has recently taken a job as a waitress at the King Kamehameha Club, and wants to hire him to help her find her missing sister, who is also a hooker. Although she is well-meaning, Leslie's 'act now, think later' ways have proven to cause nothing but problems for Thomas, and sure enough, in next to no time they are up to their necks in chaos, as they uncover that Leslie's missing sister is involved with well-known, powerful political figures...

At the 14th Annual Convention of Private Investigators, Magnum is to receive the 'Local P.I. of the Year' award, but the event is brought to a halt when Jean Claude Fornier, the famous French Detective, suddenly drops dead while giving a speech, after being poisoned. Magnum is helped - or rather, hindered - by several fellow crime-busting acquaintances as he seeks the murderer, and becomes entangled with a gang of drug smugglers, that the Inspector was hunting before he was killed...

It is almost the 4th of July, and Higgins heads to Maui for an annual writers conference, and Rick and T.C. take a trip away, leaving Thomas on the Estate to face the horror of his tax audit. But that's nothing compared to the terror yet to come when Magnum becomes the focus of a crazed, obsessed killer, who repeatedly phones him with cryptic nursery rhyme riddles of upcoming killings. At first he thinks it is a crank caller, but the full reality of the sitution hits home when a prostitute is murdered in circumstances reflecting the clues given, and the menacing calls continue, with the deranged killer boasting about his crimes and giving clues of the next one...

Magnum's ex-wife Michelle leaves her five-year-old daughter Lily to be safeguarded by Thomas, as she escapes Vietnamese assassins out to kill her and her husband, General Hue. As Thomas watches over the child, he begins to wonder why Michelle has suddenly left Lily with him and if Lily is his own daughter, and once again sets about trying to track down his elusive former wife.

When Higgins unwittingly causes Magnum to wipe an expensive computer game loaned from T.C., and Thomas accidentally erases a chunk of Higgins' memoirs stored on the computer, a feud breaks out between the pair. Magnum is trying to break a major, crooked gambling ring that is operating on the islands, but it is none too easy while in the middle of the falling out with Higgins, which starts out with each trying to out-do the other with ""eye-for-an-eye"" practical jokes, and quickly develops into a particularly bitter battle of one-upmanship...

Higgins is driving visiting Pamela Bates - an old editor friend of Robin Master's - along with her friend, and her secretary, to the Estate, when someone tries to run them off the road and over a cliff. But Pamela insists on waiting for her own mainland investigator friend famous crime mystery writer Jessica Fletcher.

The crossover continues on Murder, She Wrote S03E08 Magnum on Ice (II).

Magnum is working on a case before a date with Rick's visiting cousin, when he sees a young native Hawaiian girl become an accidental witness to a murder. With the gun-man after her, Magnum saves the young woman as they escape by diving into the sea, and is injured with a gun-shot wound in the process. He regains consciousness several days later on the remote, secluded island of Kapu, after being rescued by a native fisherman from the island, and suffering from a hazy memory of the incident. There is no sign of the girl, and the island natives insist that he was the only one found. Thomas tries to remember the events that lead to him being on the island, and what has happened to the girl, but as he tries to uncover the secrets of the island and its people, it begins to seem more and more as if they don't want him to find any answers or to leave... Meanwhile, the killer is still looking for the girl, to eliminate her as the only witness to the killing...

T.C.'s children, Melody and Bryant, come to visit him in Hawaii, but at the airport Melody goes missing. It transpires that the young girl has been kidnapped, and is held for $300,000 ransom. Magnum, Rick and Higgins help in the rush to either raise the ransom money in time, or deduct and find whoever snatched Melody. The kidnapping puts a strain on T.C.'s relationship with his son Bryant, as well as his ex-wife Tina, who quickly comes to Hawaii with her new boyfriend as soon as she hears of the kidnapping of her daughter...

Survival expert Higgins goes on a survivalist trip on an island with a small group of young offenders as part of a programme aimed at improving their self-esteem. But he has to call upon his survival skills much more than expected when a planned escape by the boys doesn't go as intended and sees the leader of the trip shot dead, leaving Higgins being hunted down on the island by the three young convicts... Back on the Estate, Magnum, with Rick and T.C., plans to take advantage of Higgins' absence by holding a big party, but the get-together seems ill-fated from the start...

1940s San Francisco: Private Investigator Thomas S. Magnum investigates the murder of newspaper tycoon William Maxfield. The case involves characters that strangely bear a strong resemblance to (modern day) Magnum, T.C., Higgins and Rick...

T.C. is giving Thomas helicopter flying lessons when he is shot. With T.C. hospitalised, Mac appears on the scene, ""volunteering"" his services to stand in running Island Hoppers. But it seems that the assailants were actually gunning for Magnum, after a week previously, somebody impersonated him when trying to blackmail a Mexican Mafia King. With Magnum marked as a dead man as a result of the mistaken identity, confusion and chaos reigns, and as per usual, Mac 'just happens' to be in the middle of it all...

After a run of bad luck, including being fired from a case investigating embezzlement, owing Rick money, and letting T.C.'s junior baseball team down, Magnum decides to get away from it all by going on a solo mountain-climbing hike, without telling anyone where he is headed. But on the climb, already suffering from a centipede bite, he discovers the wreckage of an old World War II fighter plane, only for an accident to case him to become trapped under it. With his legs caught under the wreckage, and no-one knowing he is even there in the first place, Thomas is forced to review his mortality, his values, and the case which he was fired from...

Thomas is in Chinatown with Rick and T.C. celebrating his upcoming fortieth birthday, but he has little to celebrate when he loses his lucky $2 bill that his Grandpa gave him as a boy. While looking for it, he meets a beautiful woman who may cost him not just his lucky bill, but his heart -- and possibly his life.

Rick persuades Thomas to take a lucrative, straightforward missing-person case. But the client, a New York City cop, is secretly out to avenge his young granddaughter -- and he wants Magnum's help.

Cynthia Farrell comes to Hawaii to see Magnum, and to see if the two can recapture the magic of their relationship in L.A., but when Magnum is hired by an adult film star, he spends more time looking after his case than he does Cynthia.

Magnum's P.I. license has expired. He is tied up in red tape trying to renew it when his aunt -- best-selling, Pulitzer prize-winning playwright Phoebe Sullivan -- pays him an unexpected visit. She just finished authoring a new play and is convinced someone is trying to kill her for it. Is someone really after Aunt Phoebe, or is her mind playing tricks on her?

When Ice Pick suddenly vanishes, Rick insists that Thomas find him. But things get complicated when Rick is arrested for allegedly killing a hitman who was contracted to murder Ice Pick -- and readily admits to the crime.

Thomas is delivering key evidence at the courthouse when he is shot in the parking lot by a hitman. In a coma, Thomas needs to save Michelle from some killers, and meets up with the ghost of his former Naval buddy Mac. Then he bids each of his friends a personal goodbye, in case he doesn't make it.