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

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.

A Japanese computer research company executive is recognised by a veteran as his former captor in a Phillippine prison camp in World War II.

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.

An electronics genius is busted out of prison so he can mastermind a massive robbery of diamonds from the Honolulu Diamond Exchange.

Singer Eadie Jordan has not only a comeback concert to perform, but also a serious heroin addiction. Poisoned heroin is being peddled on the islands, and McGarrett must try to save Eadie from scoring for the last time.

Five-O must act swiftly when the daughter of a top neurosurgeon is kidnapped by Wo Fat in order to make the surgeon operate on a wounded U.S. undercover agent who is carrying secret inforrmation of use to the Chinese.

Five-O must deal with treason, murder and double-crosses in order to solve the case and prevent the U.S. from being flooded by fake currency.

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.

Eddie Josephs is a paranoid schizophrenic who is carrying out murders based on old Five-O cases. McGarrett must follow his clues and catch him before more people die.

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.

Five-O's efforts to rescue a young boy from kidnappers go wrong when Kono is captured and beaten. An angry McGarrett must work out a way to rescue Kono without further endangering him.

Wo Fat and other top international agents converge on Hawaii to place bids on printing plates for twenty dollar bills, which are in the possession of a former friend of McGarrett.

Danno's past comes back to haunt him when the brother of a young boy he shot is released and wants revenge. The brother takes Chin Ho, Jenny and others hostage in McGarrett's office and threatens to blow them up, and Danno must resolve the tense situation.

An investigation into a murder is sent off track through the modification of computer information, and Five-O must use the latest technology to rescue the case.

When a deranged ex-Army officer shoots a policeman and takes a young girl hostage, McGarrett disagrees with a police captain over the best way to free her.

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.

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.

Five-O's world is shattered when mobsters catch Chin Ho undercover and order him to be killed.

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?