McGarrett is caught up in the center of a battle between the Hawaiian mob and a local faction of the union workers concerning their upcoming elections.
McGarrett must prevent a street war when the local union and the Hawaiian syndicate battle over the coming union elections.
A Honolulu policewoman vows revenge against the robbers who shot down her husband.
A group of high society men want to make sure that justice is brought to the area, and on their terms.
After an astrologist foretells the impending doom for a boxer in his next match, McGarrett must shun his skepticism to use her clues to help him with a murder case.
"Pigs on the Wing"
McGarrett seems to be the only one who doesn't buy the theory that a woman who has been suffering frightening attacks is only seeing them in her mind, and that she is mentally ill as someone is trying to convince everyone.
When a pair of surfers use a handgun to rob a shop, it leads to a painful trail of death and misery, and McGarrett must find the gun before it wreaks anymore havoc.
A pair of political terrorists have taken a policewoman hostage to use in their scheme to complete their demands. McGarrett must take them out without harming the officer.
A young psychic on vacation has a vision which leads to the whereabouts of a missing cache of $2 million in stolen jewels.
Five-O investigates when the remains of two young boys are dug up on a private Hawaiian island in order to bury them at sea and prevent an autopsy being performed.
The husband of a wealthy socialite kidnapping victim objects to the Five-O being involved in the investigation of her disappearance, fearing she will be harmed if they do.
Five-O's investigation of the kidnapping of Mrs Ames, puts her husband in a dangerous position. The kidnappers had warned him that they would kill his wife if the police were involved.
McGarrett comes up with no clues until Mrs Ames' hairdresser gives him some information.
McGarrett and the Five-O try to keep a meeting of the energy ministers on track, when a group of international forces will do anything to stop it, even an assassination.
An old counterfeiter fails to see any problems arising by using ancient $1 plates to raise money for a worthy charity.
McGarrett believes something is not right when an aide to a southeast Asian premier comes to Hawaii to bring back the $150 million in gold from the country's treasury.
A radio controlled planes are being used by clever students to smuggle priceless jewels from an exhibition in Honolulu.
McGarrett and the Five-O are drawn into the world of the Nazi regime as the investigate the murder of a famed Nazi-hunter, who's bullet riddled body was found with a rare German medal upon his chest.
The Five-O investigate why a seemingly harmless group of bird watchers are being targeted for a bloody vendetta.
A candidate for the US senate finds his campaign in peril when his blackmailer is found murdered.
McGarrett disguises himself as a famous scientist to help find a missing colleague, and finds himself locked in combat once again with Wo Fat.