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?
McGarrett is caught and cocooned, and must escape this torture and shut down Wo Fat's operation.
Victor Reese and his wife Nora are conning rich widows out of their savings, and then poisoning them and dumping them in the ocean. McGarrett and company hatch a plan to use a female officer to trap the duo.
Five-O probes into the death of an official who was instrumental in the development of the islands, and discovers a tangled web of lies and deception.
A young singer, Bobby George, plans his own kidnapping as a stunt, but when his father offers $500,000 for his release, his co-conspirators decide to double-cross him and take the money.
McGarrett and the gang must simultaneously protect a gangster from Japanese assassins and also try to convict him for his underworld activities.
Danny Williams is accused of shooting an apparently unarmed young boy. Meanwhile, in his investigation, McGarrett comes up against Big Chicken, a nasty dope dealer.
A woman buys fish from a monger, and is followed home and murdered. McGarrett and the team must discover who killed her and stop smugglers from completing their operation.
After a girl dies during a high speed chase, a trail of clues leads McGarrett to a Los Angeles prison, where he must act the part of convict Steve Crowley to gain the trust of his cellmate for a break-out, which will help reveal the plans of the crime.
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.
A winning lottery ticket drags an army private into a the murky world of mob politics and vice.
When McGarrett is shot and badly wounded on a beachside jog, Danno and the team must work feverishly to find the culprit and prevent him from committing any more murders.
McGarrett must protect a protect a mob underboss so he is able to testify against his superior, Joe Matsukino. However, Matsukino has many tricks up his sleeve to silence his former colleague permanently.
When a young female student is found murdered on campus, suspicions fall on her boyfriend but McGarrett senses that something is not right.
Danno is taken hostage by a Vietnam veteran who is suffering delusional flashbacks and sees everyone as forces sent to kill him.
Young Eadie Hastings cannot be saved by Danno from jumping of a cliff, and Five-O think that she was high on speed. They track her source to a crank teacher, Professor David Stone, and Danno must pose as a surfer to investigate the drug pushers and users.
A man is found dead after having been robbed by a motorcyclist with a gun, and McGarrett is shocked to discover that the man was suffering from bubonic plague. The islands are quarantined, and the team must follow a series of clues to discover the cause of the outbreak.
Big Chicken returns in a tense prison hostage drama when McGarrett has to give himself over to the criminals as a bargaining chip and use psychology to take control of the situation.
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.
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.
When the son of McGarrett’s sister falls ill with cancer and she becomes involved in “naturology,” her husband calls in Steve to investigate and persuade her to stop paying for the useless treatments. However, the quack doctor sets up a court case to prevent McGarrett from closing her practice.
McGarrett must use all legal means possible to win the court case against Dr. C.L. Fremont, stopping her fake treatments and saving his sister from more anguish and pain.
When a leader of a student peace movement is killed, McGarrett has to investigate the murder against a wall of silence and a distrust of the police by the activists.
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.
Sam Kalakua, a distant cousin of Kono, is being frightened into an early grave by an fake apparition of a Hawaiian god created by his nephew, who wants to sell the estate to a land merchant.
An army sergeant and a office worker have a scam in which they use bar girls to claim G.I. widow benefits, and then murder them to take the cash. McGarrett and company must use the girls to get to the core of the plot.
A Japanese World War II veteran, Yoshio Nagata, escapes from a mental hospital and tries to carry out his wartime orders to blow up a refinery.
A tsunami warning is called and a geneticist is evacuated from a conference. He is then kidnapped under the orders of Wo Fat, but he uses his diabetic medical condition as a ploy to stop Wo Fat from carrying out the plan to return him to China.
A middle-aged mainland hardware salesman uses a prostitute, and then witnesses her murder by a mobster. He refuses to testify because of the damage to his reputation and that he doesn't want to be involved. McGarrett must persuade him to do the right thing.
McGarrett must counter a threat by international terrorist Erich Stoss to use a fungus to wipe out Hawaii's sugar cane, half of the world's supply.
McGarrett must interrupt his Sunday to deal with both terrorists and politics when a revolutionary group steal guns from a barracks for their overseas cause.
A university professor, Dr. Paul Farrar, is using hypnosis to programme students into becoming assassins. McGarrett uses a policewoman as bait for Dr. Farrar, but the plan goes wrong and her life is put in danger.
Four university students hatch a plot to steal the robes of King Kamehameha, and McGarrett and the team must apply pressure to the gang's weak point to retrieve the robes and catch the thieves.
McGarrett gets a phone call from Singapore and goes to rescue Nicole Wylie, a witness who has changed her mind and wants to testify. However, the pair must face many dangers on their return trip back to Hawaii.
An assassination attempt on a prominent politician, Charles Irwin, leads Five-O to Mike Finney, a former racketeer who has been clean for nine years. However, Finney insists he is innocent, and the trail of clues leads right back to Irwin.
When a dictator's plane is diverted to Hawaii as part of a plan to kill him, McGarrett must deal with the complex politics of the situation and protect the hated leader.
When a young son of a businessman escapes from captivity by 'The Devil' and 'Mr. Frog', Five-O must recover the $300,000 ransom money that the desperate father paid.
Two young men play an increasingly dangerous and deadly game for the attentions of a beautiful but spoiled heiress, who plays them off against each other.
A career criminal, Connors, fools McGarrett and the team into protecting the wrong bank, and robs a nearby one, taking the wife of the manager hostage. Things turn ugly when one of his goons assaults and murders her. McGarrett must race to capture Connors before he can do any more damage.
McGarrett gets a surprise birthday party, but when he goes to pack the presents in his car, it explodes and blinds him. Danno, Chin Ho and Kono must work to catch those responsible, whilst McGarrett has to get used to not having his eyesight.
Two military policeman spot John Mala, a man who McGarrett has helped in the past, but who has gone AWOL. One of the policemen is shot, and tensions rise as Five-O and the army police clash in their techniques of investigation and their treatment of the local population.
A psychiatric worker, George Loomis, is trying to drive a fellow Vietnam veteran Ted Frazer crazy in order to cover up the fact that he massacred his own platoon during an action. Loomis kidnaps boys and drugs Frazer to make it look like Frazer is mad and to blame for the tragedy. McGarrett and the team must unravel this web of lies and clear Frazer.
Peter Corman is murdered during a game of poker, and his brother Lorenzo arrives in Hawaii for revenge. McGarrett must work out what happened and prevent Lorenzo from carrying out his intentions.
Chin Ho is accused of bribery, and cannot provide alibis for the nights in question. Worse, he is called to the middle of nowhere for a set-up. Chin's position is threatened, and the Governor orders an inquiry. McGarrett and the others must work out how Chin was framed and clear him of the accusations.
Lew Morgan and his wife are friends of Danno, but she is murdered, and Morgan sets out to find the culprit. However, his wife seems to be hiding secrets that may have caused her death.
A research scientist, Dr. Royce, is set up by revolutionaries to be transported away from the islands in a submarine. McGarrett must stop this from happening and also has to contend with the interference of federal agents in the case.
Dr. Alexander Kline, a biological scientist, views his work as evil, and to prove it, he plans to unleash a deadly germ that would kill thousands. Three dead cows lead McGarrett on a desperate chase to track down the toxin, involving a friendly telephone operator and top Washington agents.
Dr. Kline's deadly toxin is lost, he is having second thoughts about his plan, and McGarrett has to find the vial before it disintegrates and poisons the whole island. Already the toxin is doing its deadly work as innocent people come into contact with it.
Camilla Carver, a con-artist, blackmails a politician to take her to an event where she can steal the priceless Queen of Polynesia emerald and swap it for a fake. However, McGarrett and the team are at the event and make sure that neither the gem, Carver or her accomplice vanish.
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.
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.
Dr. Lemira, an opposition leader for Greece, is living in exile in Hawaii, but Klaus Marberg is sent to assassinate him. His plan is to get himself shot and work his way into Dr. Lemira's confidence so he can kill him easily. McGarrett must work out this plot and save the day before it is too late.
When a lawyer is murdered, his wife becomes the top suspect and McGarrett investigates. However, matters are complicated by the fact that the woman had a relationship with McGarrett, and he jeopardises his job because of this.
Shortly after giving a recital, the violin of a visiting Russian virtuoso is stolen, and McGarrett must retrieve it before the theft turns into an international incident.
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.
When a ruthless businessman is blown up in a boat explosion, Five-O has many suspects to choose from, and they use psychological methods to determine the guilty party.
A Japanese computer research company executive is recognised by a veteran as his former captor in a Phillippine prison camp in World War II.
The hitman sent to kill the witness to a two year old murder instead falls in love with her and McGarrett and the team must lead the search to find her before duty overtakes love.
Five-O search for the criminals who have set up Hawaiian singer and ecologist Jimmy Nuanu as the fall guy for a sewage plant bombing.
McGarrett and company must pit their wits against a veteran thief and robber who leaves Monopoly money at the scene of his crimes.
Dan Williams's fiancee is murdered by a strangler who writes poetry in lipstick on his victims' legs. Danno resolves to catch the culprit who has other murderous plans to carry out.
McGarrett must apprehend two abductors who are on the run with the proceeds of their crime in order to protect the lives of their co-conspirators.
When a convicted murderer, Harry Kellem, hears a dying man say he committed the crime that Kellem was jailed for, he takes a doctor hostage and McGarrett must negotiate his way out of the situation.
A cowboy fears the loss of his land to a crooked estate agent and accidentally kills him by hitting him. McGarrett and his team must track the cowboy into the mountains and persuade him to give himself up.
An electronics genius is busted out of prison so he can mastermind a massive robbery of diamonds from the Honolulu Diamond Exchange.
Five-O investigates the death of Vietnam hero Jack Rigney, who fell from a balcony. His father is a World War II veteran, but his brother Michael is a peacenik, and Danno goes undercover as a draft dodger to help solve the mystery of Jack's death.
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.
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.
The wife of an arms dealer is kidnapped by revolutionaries who want the guns diverted from their original destination, but the arms dealer himself is not as innocent as matters would indicate…
The wife of a convicted man fakes evidence in a new crime so that McGarrett will have to re-open her husband's case.
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.
A baseball player, Lon Phillips, brings his backward son to Hawaii to escape threats on his life on the mainland.
The son of the baseball player becomes the vital witness in a murder, but he is reluctant to tell either his father or Five-O of the crime.
A ten year old case is reopened when an archaeological dig unearths the skeletons of two murder victims.
Gangster Johnny Oporta arranges for his enemies to be murdered and then covers up his crimes by incinerating their bodies. McGarrett and the others must stop this murderous spree.
Vic Tanaka is murdering women and painting their faces to resemble a prostitute he once knew, who is now happily married. McGarrett and his team must find the killer before he does any more damage.
Five-O is up against a sophisticated gang who have come to Hawaii to cash $750,000 of traveller's cheques.
A hippie robs an embezzler of the key to a locker containing $250,000. Meanwhile, Danno is trying to contact the daughter of his Berkeley University landlady, who happens to be the hippie's girlfriend...
Young Vietnam veteran and marksman Billy Shem Jr. buys a rifle under false pretences and proceeds to a bunker at Diamond Head. He then takes pot shots at the people on the road and then the police who arrive. McGarrett must neutralise the threat he poses by any means possible.
While investigating the death of a security agent at an airport, McGarrett comes into contact with a gang who hijack cargo.
Five seemingly good citizens with different motives band together to steal $6,000,000 while McGarrett is away on Maui at a trial.
McGarrett finds holes in a convict's story and a husband becomes a suspect in the murder of his wife.
A policeman who was kicked off the force blames McGarrett and Five-O and plans to kill the Governor.
McGarrett must deal with the conflicts between four gangs of differing ethnic background, and try to uncover illegal activities.
A mob boss seeks revenge on a former boxer who smashed the hand of a novice to prevent him from ending up ruining his life in the boxing ring.
McGarrett and the team must find out who is behind a series of ecological stunts, when it is feared that a company executive will be their next target.
A veteran criminal who has already had dealings with Five-O escapes, and plans to steal millions of dollars from drug smugglers.
A woman attempts suicide in order to get her boyfriend to come out into the open and expose himself to an assassination attempt.
McGarrett is framed in an elaborate set up by Wo Fat, and has to contend with a foreign double amongst other problems.
Several faces from the past reappear as McGarrett must stop Wo Fat from carrying out his plan, a ninety second attack on a missile tracking base.
When a young woman is beaten and raped and a soldier is arrested for the crime, McGarrett begins to have doubts about his guilt.
An eccentric billionaire is accused of murdering a business associate, but will not leave his boat to defend himself against the accusations, allowing his associates to declare him mentally incompetent.
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.
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.
Danno goes undercover onboard a Navy ship to try and uncover how sailors are smuggling heroin onto the islands.
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.
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.
When two of a egotistical racing driver's support staff are murdered, suspicions of sabotage fall upon his attractive girlfriend.
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.
Danno shoots an apparently armed teenager but finds that he was mistaken, and public opinion and the teen's brother turn against him. McGarrett must act to defuse the potentially explosive situation.
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.
Army computer technician Jack Gulley kidnaps a scientist and then uses a planned heist by three accomplices on a military base to divert Five-O's attention from his sale of the scientist to the highest bidder.
A doctor tracking venereal disease is murdered, and Five-O must track the series of encounters to find out who is a carrier. Their investigation is made doubly important by the murder of a young woman who is close to a upcoming politician. He seems a likely suspect but McGarrett suspects a deeper plot.
Danno is found in the back of a truck, dazed and confused, and McGarrett and the others must help him piece together how he came to be in that situation.
McGarrett becomes involved with the Vashon mafioso family after the youngest member, Chris, is implicated in a daring raid on a hotel.
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.
When McGarrett arrests a group of vigilante nationalists, hidden bombs at the courthouse threaten to destabilise the islands.
A husband and wife team of scam merchants get caught between some of Hawaii's most powerful mobs.
Two drifters, Gar and Nina, steal children and sell them on to a mainland adoption agency in order to raise the cash to buy a boat and go cruising.
McGarrett agrees to let Toni, a tough female convict, get married and have a honeymoon in protective custody as long as she will testify against a local hood.
A crazed electronics wizard threatens the lives of a psychiatrist and his patients by using electronic devices and gadgets.
Five-O has a suspect for a murder, but they have one problem. How can the suspect have been in two places at the same time?
A senior partner in a stock exchange firm comes up with a foolproof plan to rob the Honolulu Stock Exchange.
McGarrett and company must break through a tissue of lies in order to protect a Russian defector from being killed.
Two simple criminals kidnap a young girl, and hide out in a bunker at Diamond Head. McGarrett must unravel the reason why they are there and get the girl safely away from them.
A travel agent who operates gambling trips is killed in order to send a warning to others that the syndicates will not tolerate competition.
Chin Ho must face the fact that his daughter, Alia, is in love with the son of a local criminal under investigation, and that she plans to get married to him.
A burglary at the home of a well known island family sets off a series of events that ends in murder.
A single person is holding out in a Five-O trial, and McGarrett and the team have to find out who is stalling and why they are doing it.
A amputee with no hands sets out to kill every police officer who contributed to his injury, and that includes Steve McGarrett.
Murders are being committed seemingly at random every six weeks, and McGarrett is at a loss to understand the motives for these crimes. However, a newspaper may hold the answer.
When a large amount of diseased rats are found on a boat with all the crew dead, Five-O must contend with an outbreak of bubonic plague.
A family of white-trash mass killers arrive on Hawaii after wreaking a trail of devastation on the mainland, and McGarrett must catch them before they can do more damage on the islands.
Buildings are being set on fire on Sundays, and a known firebug is the top suspect. However, McGarrett begins to think that others may be responsible.
A corrupt federal agent who is tracking a man under indictment for tax evasion kills him for the $600,000 he is carrying, and then loses the money.
The killing of an important pimp threatens an all out war between two competing vice empires.
A string of five murders of wealthy men leads McGarrett to a crooked inheritance scheme.
A glamorous woman sets up an opal smuggler so her accomplices can rob both the smuggler and a jewellery store at the same time.
A dictator must evade a female assassin sent to kill him, one that looks just like his own daughter.
McGarrett brings in a document expert to help him crack a case involving forged government securities, but he soon becomes suspicious of the expert as well...
A nuclear scientist becomes involved in an extortion plot when a gang threaten to explode a small nuclear weapon somewhere in Honolulu.
Harry Foxton, a gambler, is himself the subject of huge bets over what hour he will die. McGarrett must work out the gambler's complex relationships to get to the bottom of this case.
A thief known for using sleight-of-hand is hired to steal a valuable nickel, but the coin ends up on a journey across many miles and through many hands.
A mock military emergency leaves a bank open for a robbery, and Five-O must travel to the opposite side of Oahu to find out more in their investigation.
An exciting surf beach is the location for a filming session, where a man catches a killer on camera.
A pair of crooks team up with local criminals and use phony diamonds as bait to prey on wealthy male tourists. McGarrett and Five-O must shut off this sinister racket.
A young man witnesses a murder, and finds himself and his family are now the killer's targets.
The son of a Federal Narcotics officer becomes involved in a heroin refining operation.
When a man is found dead with gold dust on him, McGarrett and his team must investigate where the stolen gold came from and how it is being bought onto the market.
A series of rapes and murders occur, and the main suspect seems to be a police officer...
A right-wing crackpot, Cord McKenzie, metes out “justice” to people who have been found innocent on technicalities or released early. He thinks he is helping the police, but McGarrett thinks otherwise.
While investigating a robbery and kidnapping, the trail of clues leads McGarrett and the team to an ocean liner with a deadly passenger.
An aging jewel thief steals from rooms at Waikiki hotels, and taunts Five-O by leaving a trail of clues behind.
Danno and a college professor are kidnapped by a revolutionary group of young radicals led by a hardened criminal.
A geophysics expert, Bernard Brown, is heavily in debt, so he comes up with a plan to cause an explosion in the Hawaii Volcanoes National Park, which will cause lava to pour all down the hillside and into the city of Hilo, unless the Governor comes up with half a million dollars as a ransom.
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.
A sophisticated thief is selling his goods to legitimate businessmen, and Five-O must find a way of trapping him.
Senator Harlan Henderson suffers from multiple personalities, and one side of him wants to kill himself. However, he ends up blowing up his secretary, and McGarrett uses handwriting and a diagnosis from a psychiatrist to try to crack the case.
A criminal, Hobart, is robbing liquor stores using a policeman's former gun, but the officer wants it back as he used it to kill a bankrobber five years before and the body has been uncovered.
When his son is beaten to death, a powerful cattle baron takes matters into his own hands, and McGarrett and Five-O must prevent the rule of law from breaking down.
A gangland execution investigation takes a turn for the peculiar when it is found that the victim had two identities.
Five-O must investigate why three infallible security systems are failing to prevent the theft of priceless artworks.
After an attempt is made on Steve McGarrett’s life, he is drawn towards a female art dealer, but she too may not be good for his health…
Two conmen use a gang of Five-O lookalikes and doubles to extort money from Honolulu businessmen.
Wo Fat returns to Hawaii in order to have a Chinese diplomat whom he classes as a foolish peace-maker assassinated.
McGarrett and Five-O need to find out why a Japanese banker ritually killed himself and catch a true criminal into the bargain.
A Honolulu murder is mysteriously linked to a human fossil smuggled out of China in the Second World War.
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.
Three women desperately in need of money take to armed robbery of tourist buses as a way to raise some quick cash.
When a young boy is arrested as a witness to a murder, McGarrett must contend with a fiery deputy public prosecutor.
A million dollar reward for the return of five figurines sparks off a trail of murder and theft that leads to Hawaii.
When a psychotic man kills his doctor, Five-O must use a unfinished painting to gather clues to his whereabouts.
An elaborate sea and air scheme for heroin smuggling goes unnoticed until one of the gang tries to sell out their plan for a fix of heroin.
McGarrett must prevent a mob war by tracking down an unknown hitman and his intended target.
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.
A Saturday Night Special passes from person to person and causes Five-O trouble and others misery.
Five-O works with a air traffic investigator in order to put a stop to illegal ticket sales which have already cost several lives.
When a letter bomb kills a Naval Officer whilst McGarrett is on Navy Duty, he is called upon to investigate and uncovers a plot involving an old nemesis...
McGarrett must try his utmost to foil Wo Fat's plans which include hostages and brainwashing.
McGarrett must again face mobster Charlie Bombay when a plane carrying them to Honolulu crashes in the forests.
A British agent, Harry Wells, arrives in Hawaii in pursuit of a turncoat, but not all is what it seems for Five-O...
Five-O must find a female courier who witnessed a murder before a hitman can...
A road accident starts the trail towards a plot to use SAM missiles to bring down a VIP jet plane.
McGarrett offers himself as a hostage exchange, but is then put on 'trial' by Honore Vashon.
McGarrett meets his match in Dr. Grant Ormsbee, a grumpy and aggravating scientist who is sheltering a suspected Chinese defector.
When a singer witnesses a murder committed by a racketeer, Five-O has to protect her until she can give evidence, but this is not an easy job...
Danno's Aunt Clara becomes acquainted with a man on the plane to Honolulu, but becomes concerned about him afterwards. Dan, Steve and the others ignore her at first, but then the man turns up dead...
A vice-principal enlists the help of his students and a submarine to smuggle drugs.
When Five-O fail to prevent a series of thefts at dockside warehouses, an influential owner creates trouble for McGarrett.
A writer who specialises in solving mysteries uncovers the body in a seven year old case, but it raises more questions than it answers...
Three boys commit a gang rape on a waitress, but one is the son of a Senator and the crime is covered up...
Whilst trying to stop the smuggling of small Oriental animal statues, McGarrett is caught illegally in possession of one of them as part of his personal collection.
A disturbed young man steals nerve gas to use against a visiting royal family as revenge for the death of his father.
When an elderly importer who was a World War II Japanese spy is killed, Five-O seeks his killer.
A clear cut murder case against an island mobster is derailed due to McGarrett.
A crooked contractor and a buildings inspector are under suspicion after the new Global Trade Center in Honolulu goes up in flames.
When an airline stewardess and a hang-gliding instructor are murdered, Five-O must find the killers.
Criminals threaten to use a special type of moth to wipe out the sugar cane on Hawaii and destroy the industry.
The son of a Japanese businessman is kidnapped and held in a capsule underwater until a $1.5 million dollar ransom is paid...
Ben Tanaka, a well-known ecologist, seems to be behind the kidnapping of a wealthy land developer's wife, but all is not as it seems and a conspiracy gradually reveals itself.
McGarrett sends an undercover agent into a rehabilitation home for juvenile offenders to find out who is behind the theft of gold from dental supply warehouses.
When Wo Fat steals toxins in an attempt to take out the leaders of Communist China, McGarrett must track him to Hong Kong.
In Hong Kong, Steve is caught by Wo Fat and mentally and physically tortured by being 'reconditioned'. He must beat these problems to save the day again.
McGarrett must solve a daring bank robbery committed during the King Kamehameha Day Parade under the cover of a historic re-enactment.
The murder of island prostitutes seems to be linked to an extortion racketeer who is determined to make a return...
Five bodies are found in the crater of Mauna Loa contaminated by radiation from illegal plutonium, and Five-O must find and confiscate this deadly toxin.
Two seemingly unconnected deaths lead McGarrett into a desperate race to prevent the assassination of a visiting Sheikh.
A masterful forger plans a massive robbery of Navy funds, and McGarrett is made to look rather inept...
When yacht racers are found dead on their craft, Five-O launches a desperate search for high-seas buccaneers.
A escaped convict may well have a strong case of innocence, when Five-O become involved in the paranormal...
A press photographer is pursued relentlessly after she takes a photo of a supposedly dead gangster who has returned to the islands to take control of the local syndicate.
When $10 million goes missing from a crimelord, the culprit seems to be dangerously close to home...
Police are being lured into traps and shot, and Five-O have difficulty nailing a suspect when their primary lead turns out to be a paraplegic.
The boyfriend of an overdose victim re-enacts famous film murders in a revenge on all the people he sees as responsible.
McGarrett is the top suspect in the murder of his girlfriend, and the evidence against him is seemingly overwhelming...
Five-O must work with a Japanese officer to find the source of handsguns that are flooding the black market in Tokyo.
The daughter of Attorney General John Manicote is kidnapped by a deranged rapist and murderer, and Steve must not only contend with the criminal but Manicote's emotional state as well...
A hit and run incident leads Five-O to a gambling syndicate and Officer Welles's brother.
A pensioner threatens to blow himself and his hostages up if he doesn't stop the demolition of his home.
A lady singer is kidnapped and it looks as if she and her captors have died at sea.
A gangster attempts to buy an interest in a football club so that he can launder money through it.
While searching for parts from a sunken Soviet submarine, McGarrett become suspicious about the particular parts that are being recovered.
A missing rodeo cowboy and the murder of a young couple pose a puzzling mystery for Five-O.
The daughter of a LA detective and friend of McGarrett is framed for murder and then joins a cult.
A gang of thieves steal army rifles by peculiar means - hang-gliding into the armoury!
An Irish terrorist uses disguise and deception in order to be able to smuggle explosives for the Troubles.
When a sea-freighter is hijacked, the wealthy millionaire owner calls in Five-O, but all is not how it seems...
McGarrett must solve both a mysterious kidnapping and the problem of having a nosy reporter analysing his every move.
McGarrett engages in a personal struggle to clear the record of an officer and close friend accused of criminal activity.
Five-O must find out whether the death of an archaeologist is linked to his supposed desecration of tomb of King Kamehameha.
The return of a disgraced alcoholic policeman causes extra problems in the pursuit of a pair of armoured truck robbers.
McGarrett must deal with an astronaut turned real-estate salesman in order to crack the case of a murdered reporter.
When a Russian tennis star wants to defect, McGarrett must work to prevent an international incident.
A secret submarine, the murder of a Navy officer and strange amnesia create a puzzling case for Steve McGarrett.
A gang of university students plan a hoax tidal wave in order to steal priceless jewellery.
When an Asian ex-leader dies in a seemingly accidental swimming incident, his wife is convinced that he was murdered by forces from their home country.
McGarrett becomes involved in a love triangle between a young local man, a rich girl and her father who hates the Hawaiian origins of the boy.
A young doctor is suspected of having been involved in the murder of his mentor.
In order to find out the identity of the murderer of a union leader, McGarrett goes undercover as a longshoreman.
An up-and-coming young politician is blackmailed in order to affect his leadership of an congressional investigation.
While pursuing a drug dealer, McGarrett also has to contend with a federal agent.
Danno must deal with a surfer, one of his friends, who is suspected of the murder of a girl.
A female undercover cop threatens the progress of an investigation when she starts a relationship with a man connected to the case.
A Japanese businessman comes under attack from a young man whose father suffered in an Japanese Prisoner of War camp.
McGarrett must deal with an apparent mass murderer when a will creates a fortune for the last family member left alive.
A cryogenics institute comes under suspicion when an investigative writer becomes involved.
Five-O must deal with the kidnapping of an Arab princess, and Steve must also deal with an Italian female journalist's constant interruptions.
Five-O become involved in a complex case of body-switching, mystery investments and suitcases full of money.
Five-O's world is shattered when mobsters catch Chin Ho undercover and order him to be killed.
After a government agent is murdered, McGarrett must identify the traitor in a scientific facility.
When an astrologer visits McGarrett to inform him of a murderer with a terrible temper, his antagonism lessens when her assumptions seem to be partly true.
While McGarrett follows a false lead, an undercover Danno is discovered and brainwashed to carry out the assassination of Steve...
McGarrett is the lone hold-out in a trial where the guilt of the accused seems certain.
Steve is framed on the orders of a gambling syndicate, and becomes involved with a woman who is part of the case.
Five-O must deal with the plans of a Neo Nazi organisation to kill Bobby Tamara, the "Hawaiian Kennedy".
When a street robber claims that he stole King Tutankhamun's mask for fun, McGarrett suspects there is more to the case than simple robbery.
McGarrett assists a convict in his escape, so that he can go back to his gang and provide Five-O with inside information.
Danno is surprised when he bumps into a former flame and even more concerned when she seems to be involved in criminal activities.
The death of a prominent politician reveals a strange love triangle.
When a preacher is attacked by a man convinced that he is responsible for his wife's death, Five-O investigate more closely and discover some less than godly motives.
Two rival mobs attempt to take control of the disco scene in Honolulu.
The rival gangs are on the brink of all out war, and Five-O must struggle to stop them.
When a robbed bank vault shows no signs of break-in, an inside job seems the likely solution. McGarrett's trail of clues leads him back to the builder of the vault and his wife...
Millicent Shand returns and claims that her niece's husband has faked his own death in order to get his hands on $500,000.
A vacationing heiress seems unconcerned when McGarrett warns her that someone is after her ruby.
When a photographer takes a picture of a politician making a deal with an underworld figure, he tries blackmail. However, he is not prepared for the ruthless nature of the mobsters.
A private detective is rescuing girls from prostitution, and using the opportunity to kill the pimps as well.
When the son of one of Steve's friends dies of an overdose, he goes after a doctor that he suspects of over-prescribing drugs.
The hunt for a high-rise killer is made more difficult for Five-O when a journalist offers to share his profits in exchange for the killer's story.
When a woman dies due to heroin packets bursting inside her and the Governor is implicated, McGarrett and Danno head off to Singapore to discover a smuggling operation.
Five-O must close the heroin smuggling operation to exonerate the Governor and catch the figures behind the scheme.
McGarrett finds himself stymied when Hawaiian nationalists and local underworld mobsters clash over a union election.
Labouring under a ban on cooperation by native Hawaiians because of a Kahuna, McGarrett must try to prevent war on the streets...
When the husband of a policewoman is gunned down by opportunist robbers, she resolves to catch them any way she can.
A group of high society men set out to see that justice is done - the catch being that it is justice on their terms only...
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...
When two surfer bums use a gun to rob a shop, it starts off a trail of death and misery involving children, politics and blackmail.
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.
A young man on vacation has strange visions that lead him to the site of an old murder and help him discover a lost family.
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...
McGarrett and Kimo must stop a gang of trained assassins from disrupting a meeting of energy ministers.
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.
A gang of clever students use radio-controlled planes to execute the theft of Queen Liliokalani's jewels.
The murder of a Nazi-hunter and discovery of a World War II medal set McGarrett and the team on the trail of a Nazi war criminal living in Honolulu...
A group of seemingly harmless birdwatchers are the target of a vendetta. Five-O must discover why they were a target and stop any further violence.
A politician trying for the Senate is weakened by the murder of the man who is blackmailing him.
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.
