Air date - Fri 20th of September 1968
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?
Air date - Fri 20th of September 1968
McGarrett is caught and cocooned, and must escape this torture and shut down Wo Fat's operation.
Air date - Thu 26th of September 1968
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.
Air date - Thu 3rd of October 1968
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.
Air date - Thu 10th of October 1968
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.
Air date - Thu 17th of October 1968
McGarrett and the gang must simultaneously protect a gangster from Japanese assassins and also try to convict him for his underworld activities.
Air date - Thu 7th of November 1968
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.
Air date - Thu 14th of November 1968
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.
Air date - Thu 21st of November 1968
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.
Air date - Thu 5th of December 1968
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.
Air date - Thu 12th of December 1968
A winning lottery ticket drags an army private into a the murky world of mob politics and vice.
Air date - Thu 19th of December 1968
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.
Air date - Wed 25th of December 1968
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.
Air date - Wed 1st of January 1969
When a young female student is found murdered on campus, suspicions fall on her boyfriend but McGarrett senses that something is not right.
Air date - Wed 8th of January 1969
Danno is taken hostage by a Vietnam veteran who is suffering delusional flashbacks and sees everyone as forces sent to kill him.
Air date - Wed 15th of January 1969
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.
Air date - Wed 22nd of January 1969
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.
Air date - Wed 29th of January 1969
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.
Air date - Wed 5th of February 1969
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.
Air date - Wed 12th of February 1969
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.
Air date - Wed 19th of February 1969
Air date - Wed 26th of February 1969
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.
Air date - Wed 5th of March 1969
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.
Air date - Wed 12th of March 1969
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.
Air date - Wed 19th of March 1969
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.