24 episodesFirst aired 9 September 1974
E1Sept 19741h
Danno and a college professor are kidnapped by a revolutionary group of young radicals led by a hardened criminal.
E2Sept 19741h
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.
E3Sept 19741h
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.
E4Oct 19741h
A sophisticated thief is selling his goods to legitimate businessmen, and Five-O must find a way of trapping him.
E5Oct 19741h
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.
E6Oct 19741h
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.
E7Oct 19741h
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.
E8Oct 19741h
A gangland execution investigation takes a turn for the peculiar when it is found that the victim had two identities.
E9Nov 19741h
Five-O must investigate why three infallible security systems are failing to prevent the theft of priceless artworks.
E10Nov 19741h
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…
E11Dec 19741h
Two conmen use a gang of Five-O lookalikes and doubles to extort money from Honolulu businessmen.
E12Dec 19741h
Wo Fat returns to Hawaii in order to have a Chinese diplomat whom he classes as a foolish peace-maker assassinated.
E13Dec 19741h
McGarrett and Five-O need to find out why a Japanese banker ritually killed himself and catch a true criminal into the bargain.
E14Jan 19751h
A Honolulu murder is mysteriously linked to a human fossil smuggled out of China in the Second World War.
E15Jan 19751h
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.
E16Jan 19751h
Three women desperately in need of money take to armed robbery of tourist buses as a way to raise some quick cash.
E17Jan 19751h
When a young boy is arrested as a witness to a murder, McGarrett must contend with a fiery deputy public prosecutor.
E18Feb 19751h
A million dollar reward for the return of five figurines sparks off a trail of murder and theft that leads to Hawaii.
E19Feb 19751h
When a psychotic man kills his doctor, Five-O must use a unfinished painting to gather clues to his whereabouts.
E20Feb 19751h
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.
E21Feb 19751h
McGarrett must prevent a mob war by tracking down an unknown hitman and his intended target.
E22Mar 19751h
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.
E23Mar 19751h
A Saturday Night Special passes from person to person and causes Five-O trouble and others misery.
E24Mar 19751h
Five-O works with a air traffic investigator in order to put a stop to illegal ticket sales which have already cost several lives.
