Air date: 1974-09-10

Runtime: 60 min

Danno and a college professor are kidnapped by a revolutionary group of young radicals led by a hardened criminal.

Air date: 1974-09-17

Runtime: 60 min

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.

Air date: 1974-09-24

Runtime: 60 min

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.

Air date: 1974-10-01

Runtime: 60 min

A sophisticated thief is selling his goods to legitimate businessmen, and Five-O must find a way of trapping him.

Air date: 1974-10-08

Runtime: 60 min

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.

Air date: 1974-10-15

Runtime: 60 min

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.

Air date: 1974-10-22

Runtime: 60 min

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.

Air date: 1974-10-29

Runtime: 60 min

A gangland execution investigation takes a turn for the peculiar when it is found that the victim had two identities.

Air date: 1974-11-12

Runtime: 60 min

Five-O must investigate why three infallible security systems are failing to prevent the theft of priceless artworks.

Air date: 1974-11-26

Runtime: 60 min

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…

Air date: 1974-12-03

Runtime: 60 min

Two conmen use a gang of Five-O lookalikes and doubles to extort money from Honolulu businessmen.

Air date: 1974-12-10

Runtime: 60 min

Wo Fat returns to Hawaii in order to have a Chinese diplomat whom he classes as a foolish peace-maker assassinated.

Air date: 1974-12-31

Runtime: 60 min

McGarrett and Five-O need to find out why a Japanese banker ritually killed himself and catch a true criminal into the bargain.

Air date: 1975-01-07

Runtime: 60 min

A Honolulu murder is mysteriously linked to a human fossil smuggled out of China in the Second World War.

Air date: 1975-01-14

Runtime: 60 min

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.

Air date: 1975-01-21

Runtime: 60 min

Three women desperately in need of money take to armed robbery of tourist buses as a way to raise some quick cash.

Air date: 1975-01-28

Runtime: 60 min

When a young boy is arrested as a witness to a murder, McGarrett must contend with a fiery deputy public prosecutor.

Air date: 1975-02-04

Runtime: 60 min

A million dollar reward for the return of five figurines sparks off a trail of murder and theft that leads to Hawaii.

Air date: 1975-02-11

Runtime: 60 min

When a psychotic man kills his doctor, Five-O must use a unfinished painting to gather clues to his whereabouts.

Air date: 1975-02-18

Runtime: 60 min

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.

Air date: 1975-02-25

Runtime: 60 min

McGarrett must prevent a mob war by tracking down an unknown hitman and his intended target.

Air date: 1975-03-11

Runtime: 60 min

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.

Air date: 1975-03-18

Runtime: 60 min

A Saturday Night Special passes from person to person and causes Five-O trouble and others misery.

Air date: 1975-03-25

Runtime: 60 min

Five-O works with a air traffic investigator in order to put a stop to illegal ticket sales which have already cost several lives.