Jessica Humboldt, an astrologer and friend of Agnes DuBois, comes to McGarrett with news that a forthcoming match will be disastrous for a boxer. McGarrett must overcome his suspicions and crack the case.
Tony Alika and Guido Marioni, killer of Kimo's family, together hatch a plot to frame and embarrass the Five-O team by making them look stupid or corrupt.
When a woman is stalked by a strange figure, she seems to be seeing things and her friends are worried as to her mental health. However, events prove her case and an accomplice is revealed...
A group of terrorists capture a female officer and use her to further their aims, and McGarrett and the team must find a way to take them out without endangering the life of Officer Dean.
When two healthy young people die mysteriously, local traditions prevent post mortems, and a strange conspiracy is gradually uncovered when Truck seems to fall under the power of a Kahuna...
When a rich socialite is kidnapped, her husband insists that Five-O stay out of the case. However, his reasons may not all be on the level as events take a series of twists and turns...
A aging crook decides to use dollar bill printing plates he made to raise cash for a charity, but he fails to realise the trouble that this will cause.
McGarrett is suspicious of an aide who arrives in Hawaii to retrieve millions of dollars held in trust for a Southern Asian state and he must prevent a daring gold robbery.
The series concludes with the final showdown between McGarrett and Wo Fat. Three scientists have gone missing. They have one thing in common: they all attended a symposium that discussed a possible space-based, laser defense system. McGarrett impersonates a fourth scientist, Dr. Elton Raintree, who attended the same gathering and is soon abducted. Wo Fat is behind it all and wants the scientists to complete their work and produce such a device.