A band of young radicals is killing ordinary people at random. Five-O consults an academic who is knowledgeable about such groups. The group then kidnaps Dan Williams and the academic, threatening to kill both men.
A man who's an expert in both geology and explosives, owes loan sharks more than $72,000. He has planted explosives that, if set off, will cause volcanic eruptions and is demanding $500,000 from the state of Hawaii. He has killed accomplices and is prepared to go through with his threats. But he doesn't know his fed-up wife is preparing to double cross him.
A nerdy bookstore clerk with an obsession for McGarrett turns deadly as he re-creates some of Five-O's most famous cases that were covered in a series of magazine articles. He is so brazen that he even calls McGarrett to brag about his crimes and sends him notes. Now McGarrett and the rest of the Five-O team must find the killer before he strikes again.
Colby runs an operation that fences stolen goods with retailers enticed by too-good-to-be-true prices. Five-O enters the case when the body of a federal law-enforcement agent -- killed during a robbery on the Mainland -- is discovered in a refrigerator shipped to Hawaii. McGarrett & Co. turn up the heat as the body count increases.
A current wave of liquor store robberies and shootings are strangely linked to a fiveyear old bank robbery in which neither the quarter-million-dollar booty nor the thief was ever found. Charles Cioffi guest stars as an HPD officer, who, when the link in the crimes is uncovered, desperately hunts for the man behind the liquor store crimes.
A politically powerful Big Island rancher learns that his son was killed by a blow to the head. The son was involved in a fight outside a barroom with a local. The local is arrested and, over the rancher's strenuous objections, charged only with manslaughter. The rancher plots to break into the jail and kidnap the suspect, hide him on the huge ranch and ceremoniously hang him from a tree. While Five-O frantically searches for the unlucky suspect, McGarrett finds a rock at the crime scene with blood on it. "This wasn't manslaughter, Danno ... this was murder one!" He ...
A Honolulu businessman is found murdered on a land tract he was trying to develop. The case has all the earmarks of a syndicate hit. Five-O traces the dead man and finds that he was, in fact, a former thug who had testified and gone into the Federal witness protection program. But they find this out so easily that McGarrett begins to suspect that the mob had nothing at all to do with the murder -- someone close to the witness, who knew all about his history, killed him and pinned it on the mob. Suspicion soon falls on the dead man's wife and her lover, who were to be ...
Thugs break into the heavily-guarded art room of a multimillionaire and steal a Gauguin painting worth a fortune. When Five-O comes to investigate, the millionaire, his secretary and his grandson (who are the only inhabitants of the mansion) are surprisingly uncooperative. It turns out that the old man had been planning to sell the painting and had hired two art appraisers to market it. Soon, the group receives a ransom demand. The grandson figures out a way to pay the ransom despite intense Five-O surveillance -- with grandfather, grandson and secretary all leaving ...
A plaque, an award for his work in law enforcement, arrives in McGarrett's office and promptly explodes, killing one officer and injuring McGarrett. The perpetrator soon discovers McGarrett survived and begins planning his next attempt.
A pair of con men sneak into Five-O' headquarters at night to photograph the layout of the offices. They then use these photos to duplicate the offices in an abandoned building, and also hire actors to impersonate McGarrett and the other members of Five-O, as part of an elaborate scheme to extort money from businessmen who may not be aware of the real location of Five-O, nor personally acquainted with its top operatives.
A top Chinese official is visiting Hawaii for an important conference. He wants to visit the circus, creating a massive security headache for Five-O. Meanwhile, Wo Fat has now broken from the Chinese government. He opposes how China is "on bended knee" to negotiate with the United States. As a result, Wo Far has organized a complicated assassination plot.
A shamed Japanese banker ritualistically kills himself, and McGarrett want to know why. McGarrett demands answers from a prominent financial consultant, played by guest star Ossie Davis, and the deceased's assistant when Five-O discovers the pair are involved in an international swindle.
Raymond Parmel, a murderous former soldier, claims to have the remains of Peking Man, the fossilized bones of prehistoric humans found in China in the 1930s that disappeared shortly after the attack on Pearl Harbor in 1941. McGarrett must deal both with him and with a professor who represents the government of the People's Republic of China, which wants to recover the bones as a Chinese national treasure, and doesn't care whether Parmel is captured or not.
After killing a drug dealer who stiffed her, an impoverished psychotic woman asks her friends (who are in similar dire financial straits) to go with her on a scheme to rob tour buses for the valuables the tourists are carrying. The other two women agree, but things go south when the leader, Dina, starts using her big .45 automatic far too many times.
A hit man takes a shot at a man on a boat arriving in Honolulu harbor from a distance of about a half mile, using an old tower on Sand Island as his sniper's nest. An apparently homeless boy named Moki, however, witnesses the hit man as he fires the shot. The hit man gives chase, but Moki escapes. McGarrett manages to locate the boy and sends him to juvenile detention for his own protection, but he does not figure on the intervention of Frances Chai, a crusading deputy public defender.
Colin Nichols is a vicious British soldier of fortune, looking for a missing art object that is part of a set of ancient Hindu figurines known as the "Ring of Life." He tortures and kills one man in Hawaii in pursuit of the missing piece, hoping to claim a $1 million reward from the government of India for return of the stolen item. The murder brings McGarrett and Five-O into the case, but it turns out that Nichols is not the only one after the missing artifact or the reward.
Mike (Richard Hatch) carries a torch for Glynis (Gretchen Corbett) and concocts an elaborate scheme, involving multiple murders, so that they can be together. To catch the killer the Five-O team must analyze a surreal painting a psychiatrist made of Mike's disturbed mental state.
A skydiver and a private pilot team up to retrieve heroin shipments from the ocean and then airdrop them onto Oahu, in order to evade a recent tightening against drug smuggling into Hawaii. McGarrett and Five-O learn that there is something afoot when an addict who knows of their plan is gunned down in a telephone booth as he tries to warn Five-O.
A paranoid Korean War veteran, thinking a policeman is about to arrest him for a crime he didn't commit, grabs the officer's gun and shoots him. More cops appear, so the vet pulls the wounded officer's ammunition belt free and runs into an apartment occupied by a teenage girl, locking himself and the girl inside. McGarrett and HPD's SWAT team arrive at the same time, and the leader of the SWAT team wants to blast his way into the apartment and take down the gunman, who blazes away at targets all over the place. Because somehow the gunman hasn't killed anybody yet, and...
One of the better of far too many TV-series episodes advocating gun control, as four owners of a single Saturday Night Special automatic use it for death and destruction (including, in one case, a child shooting himself). Ramon Bieri, the lone credited "guest star" imported from the mainland, plays a postal worker who finds the weapon and goes postal with the gun on his wife and her lover. Stuntman and many-time bit player Beau Van Den Ecker has the second-largest role as a thug who uses the weapon in the last 15 minutes of the show to rob and shoot up convenience ...
A criminal syndicate has stolen 6,000 airline, cruise and attraction tickets and is now shoving them down the throats of travel agencies, forcing them to pay for them and then "eat" them to avoid taking the blame for stealing stolen merchandise. To make sure the travel agencies stay in line, one of them is bombed, killing three people. An undercover agent from the mainland helps Five-O infiltrate the gang. The only chance you will get to see similarly-named actors Jack Hogan (who gets top billing because he was a regular on "Sierra" at the time of filming; he plays ...