[1] After the brides of three G.I.s killed in Vietnam turn up dead, the Five-O team uncovers an insurance scam run by a sergeant with a murderous grudge.

Fear spreads through Hawaii after rumors of a supposed imminent tsunami, but McGarrett discovers the true threat: the villainous Red Chinese agent Wo Fat has kidnapped a renowned geneticist (Will Geer) and plans to use the scientist's discoveries to create a superior race.

A surprise birthday party for McGarrett ends with a bang--a car-bomb explosion of his black 1968 Mercury Park Lane Brougham.

When Chin Ho Kelly is accused of taking a bribe from a drug dealer, the Five-O members defend one of their own.

Ed Flanders, Loretta Swit, Joseph Sirola, Dana Elcar, Karl Swenson, H. M. Wynant guest star.