When an ex-surfing champion, who was a friend of Magnum, Rick, and T.C.'s, is found dead on the beach, Magnum becomes concerned that the Police are not treating the case importantly enough and investigates the suspicious death for himself. During the course of his investigations, a local small-time drug supplier and an emotionally disturbed Vietnam veteran both stand out as prime suspects, but Thomas suspects that the culprit is someone else...

Although he's nearly mowed down by a private plane that crashes into the estate's tidal pool, Thomas befriends the pilot, Sam Hunter, who was delivering the plane to its new owner, Mr. Sato; both men have an inkling that they've met before but can't seem to remember where or when, and Thomas has a nagging feeling that he owes Sam one, even though he can't place his finger on why; after Higgins and Thomas are shot at when they catch someone snooping around the plane, Thomas searches through the wreckage and discovers that the crash was caused by sabotage; Sam returns to Texas for his son's birthday, and attempts to reconcile with his ex-wife; after Thomas lets him know about the sabotage and that an investigation into Sato's background reveals that he's a major cocaine importer, Sam takes to the air to track down Sato and Nick, the coworker he suspects of causing the plane crash; a bit of fancy flying later, Sam forces the plane carrying Nick, Sato, and a cargo of cocaine to land right in

Magnum is hired by an attractive woman to find the missing will of her late father, who was recently killed in a suspicious boating accident - which she suspects her brother of being behind, in order to steal the will. Working on the case, Thomas finds that former client Susan Johnson – whom he was once locked in a bank vault with – is now a fellow Private Investigator, and is working on the same case – for the brother, who suspects his sister as responsible for their father's death. The two P.I.s are soon locked in a battle of wills as they both race to solve the investigation first, but the pair are forced to put their rather love-hate relationship to one side and team up to solve the case of sibling rivalry...