A beautiful leading fashion designer hires Thomas to protect her when one of her two partners in their designer clothing company is murdered, and she suspects that the other partner may have been behind it. But the assignment proves tricky as several people had a strong enough motive for the murder, and someone is planning a revenge killing...

Magnum is on the sea-front, watching the approaching storms brought on by the Kona Winds, when he sees a woman either slip or jump into the turbulent waters. After rescuing her, he takes her back to the estate, where she tells him that the previous night, she witnessed her husband - owner of a reel-estate empire - murder his business partner, and now fears that he'll kill her too. As Thomas investigates her husband, he begins to fall in love with the woman, but as he observes, the Kona Winds make people behave in uncharacteristic ways, and the whole situation spells big trouble and danger for him...

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 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...