McGarrett must contend with Honore Vashon, who wants revenge for his son's death.

Dominick Vashon, the patriarch of the clan, makes his attempt to bring down McGarrett and Five-O.

McGarrett becomes involved with the Vashon mafioso family after the youngest member, Chris, is implicated in a daring raid on a hotel.

Wo Fat is suspected of being behind the theft of a mobile ICBM device, and McGarrett with other top officials must stop him selling it off to the highest bidder.

A crazed electronics wizard threatens the lives of a psychiatrist and his patients by using electronic devices and gadgets.

Five-O is up against a sophisticated gang who have come to Hawaii to cash $750,000 of traveller's cheques.

A policeman who was kicked off the force blames McGarrett and Five-O and plans to kill the Governor.

A veteran criminal who has already had dealings with Five-O escapes, and plans to steal millions of dollars from drug smugglers.

McGarrett and company must pit their wits against a veteran thief and robber who leaves Monopoly money at the scene of his crimes.

When a young woman is beaten and raped and a soldier is arrested for the crime, McGarrett begins to have doubts about his guilt.

A local thug, Piro Manoa, is trying to create the impression of corruption in the Five-O force, and Duke is implicated in a murder. McGarrett and the team, with new recruit Ben Kokua, must save Duke's position and work out the plot of the organisation behind the false accusations.

A husband and wife team of scam merchants get caught between some of Hawaii's most powerful mobs.

Chin Ho and Dan Williams are tracking a safecracker but he pulls a gun and Danno ends up shooting him. McGarrett takes his identity of Harry Brown and must infiltrate a sophisticated gang of international thieves.

McGarrett is framed in an elaborate set up by Wo Fat, and has to contend with a foreign double amongst other problems.

McGarrett sets up a cordon of police around a young woman to capture her boyfriend who has escaped from jail, but all is not as it seems…

A young widow becomes part of a blackmail plot involving the murder of a Chicago mobster.

A private investigator, Sam Tolliver, arrives from Texas to help an old friend who is being blackmailed and is at risk of being killed if he doesn't pay up, but he ends up wanting to become part of the blackmail operation.

When a singer, Joey Rand, finds that his career doesn't pay well enough, he turns to cat burglary. However he doesn't reckon on Hawaii Five-O.

When the boxing son of a policeman, Phil Kalama, is killed, he starts a personal vendetta, and McGarrett must both solve the crime and stop Kalama from committing another murder.

Five seemingly good citizens with different motives band together to steal $6,000,000 while McGarrett is away on Maui at a trial.

Three real estate crooks die horrible and mysterious shellfish related deaths, and McGarrett and the others must establish the link between them, and who has reason to want them dead.

A psychotic man named Ralston is killing the wives of members of his army unit, and Five-O, including Kono on his last case, must stop him before he commits any more crazed attacks.

Red Chinese agent Wo Fat uses a sensory deprivation chamber to procure information from U.S. agents. Steve McGarrett, head of Hawaii Five-O, investigates the death of a close friend who appears to have drowned. Steve's knowledge about his friend and a mysterious white substance lead him into a high-level intelligence matter involving a foreign agent. McGarrett, head of Hawaii's state police force, poses as "control," possessor of the names of other agents. He allows himself to be captured and placed in the chamber; will he be able to withstand the torture?

A winning lottery ticket drags an army private into a the murky world of mob politics and vice.

When a girl is found murdered and numbered 'one', McGarrett suspects a serial killer. However the killer seems to be very selective in targeting members of a particular company, and suspicion soon falls on two brothers who stand to inherit the firm from their aged aunt.