Thomas finds himself 45 years in the past, in a dream that seems so real that at first, he is certain that Higgins is pulling some sort of practical joke on him. Trapped in this 1936 Hawaii, he is working on a case for a ""dame in trouble"" - a young woman who's father, a union leader, has been accused of the murder of a construction magnate. Thomas encounters 1930s versions of Higgins, Rick, and T.C. as he tries to find the evidence needed to clear the girl's father...

When a plucky cocktail waitress is denied permission to scatter her late father's ashes at the Arizona Memorial, Pearl Harbour, and faces arrest if she tries to do so, Lt. Maggie Poole advises the woman to contact Magnum. Soon, Thomas finds himself investigating a forty-year-old court martial ruling that decided the woman's father was AWOL during the Japanese raid on Pearl Harbour...

T.C. and Magnum train their respective junior basketball teams for an upcoming game. T.C.'s team seems to have the advantage until Magnum meets a plucky teenager with a great game, and persuades her to join his team. Magnum and Higgins take a shine to the girl, and discover that her foster parents are criminals who are using her as a pawn in running their con games.

To smoke out the thief in a large family-owned business, Thomas feigns marriage to the CEO's niece, who drives a mean limousine and can't quite make up her mind how she feels about men, marriage and Magnum.

Eager to attend a ten day Tiger home stand, Thomas convinces T.C. to finance the expenses for the trip in exchange for Thomas's collecting the $10,000 fee that T.C. was stiffed by a man from Motor City, and handing T.C. the keys to the Ferrari while he's gone; while tooling around in the car, T.C. literally runs into Leon, a fellow Vietnam vet turned professional boxer, and his young daughter Ima; feeling responsible for Leon's broken collarbone, T.C. offers to take his place in the two remaining club fights Leon needs to win to claim the purse that will lift him out of his financial difficulties; T.C.'s eagerness to substitute for Leon dims when he learns that these are bare-knuckle, no-holds-barred fights, and that there are many more than two fights he must win before collecting Leon's purse from a promoter who turns out to be crooked; back in Detroit, Thomas is having more difficulty than he anticipated collecting T.C.'s debt and attending a game, until two strangers in a bar take

The Crown Prince of Jororo accompanies his teammates when their baseball team comes to Hawaii to play T.C.'s team, and takes up residence on the estate as a safety precaution against the death threats he's received. Thomas strikes up a friendship with the boy, who is eager to escape the ever watchful eyes of his bodyguards and governess, and who has a nasty habit of escaping whenever the opportunity presents. When terrorists attempt to assassinate the young prince, Thomas goes all out to protect him from his father's enemies, who turn out to be closer than anyone imagined.

Higgins sustains a concussion hours before the guests are to arrive for a charity gala at the estate, and begins to lapse in and out of believing he is famed Shakespearean actor Sir Fearing Pangborn; Thomas enlists Rick and T.C. to cover security for the event while he takes up the slack left by Higgins's injury, and has his hands full when all the guests, dressed as famous characters of the 1920s in keeping with the gala's ""Great Gatsby"" theme, begin to arrive hours ahead of the appointed time; a crime wave breaks out when someone dressed in the same Charlie Chaplin costume as Rick is seen fleeing from a guest's room moments before thousands of dollars in cash and jewelry are reported missing and an addled Higgins is the prime suspect in the murder of one of the guests; as he begins to realize that people and events are not what they seem, Thomas takes his inspiration from the six-hour First Annual KHKU Agatha Christie Film Festival he viewed the previous night to solve the crimes a

As he's about to take off after delivering a pair of newlyweds to Maui, T.C. is offered a lot of money to deliver a briefcase to Oahu. On his approach to the Island Hoppers headquarters, he loses control of his helicopter and crashes into the ocean. After being rescued by fishermen, T.C. is rushed to the hospital, where he remains in a coma with his brother Gerald at his side. When the Coast Guard is in no rush to investigate what they consider to be a simple accident, Thomas and Gerald investigate the chopper's wreckage and discover that it was shot down. Thomas, Higgins, Rick and Gerald put their own lives in jeopardy as they set out to find who's responsible for T.C.'s near-fatal crash.

At the urging of the students in the private investigation class that Thomas is teaching at a local college, Thomas takes on the investigation into the disappearance of a fellow student's fiancé as the class's field work. The teacher and his pupils soon discover that while the student's fears that her fiancé is having an affair are unfounded, this anything-but-textbook case involves a man sought after by both sides of the law for trying to prevent a crime.

Robin and Higgins simultaneously ask Thomas to do some investigative work, so Thomas calls on Luther to nail the man who's blackmailing Higgins over information that could have repercussions for him and an old flame in the House of Commons, while Thomas goes undercover to investigate embezzlement in a bank owned by Robin's friend.

Thomas meets up with an old friend from high-school, Goldie Morris. He finds that she has lost her rather goofy looks from her younger days to become an attractive woman, but hasn't lost any of her extremist protestor ways – something that comes to the fore when she voices her disapproval when learning that he is delivering some important papers on behalf of Higgins to a visiting unpopular third-world President, known for living a luxurious life while letting many of his people starve. But Goldie has a job for Thomas, hiring him to find a trained dolphin that was recently kidnapped from a local sea life park. She admits that she was part of a liberation group that took the dolphin, planning set it free, but it becomes apparent that the two men that were in on the dolphin-napping plan to use the highly-trained creature in a far more sinister plot...

Magnum and a group of his treasure hunting friends are held at gun-point on a cliff-top with the one million dollar prize that was the hidden object of a treasure hunt competition, organised to help promote Robin Masters' new novel by using clues from it. Thomas recounts how they winded up in this predicament: he had been hired by the woman overseeing the treasure hunt to protect her throughout the contest, after it seems that someone is prepared to go to any extent, even to kill, to win the prize money...

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...