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

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…

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

McGarrett must again face mobster Charlie Bombay when a plane carrying them to Honolulu crashes in the forests.

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...

When an elderly importer who was a World War II Japanese spy is killed, Five-O seeks his killer.

When yacht racers are found dead on their craft, Five-O launches a desperate search for high-seas buccaneers.

When $10 million goes missing from a crimelord, the culprit seems to be dangerously close to home...