House Un-American Activities Committee investigators Jim McLain and Mal Baxter come to post war Hawaii to track Communist Party activities even though belonging to the party was legal at the time. They are interested in everything from insurance fraud to the sabotage of a U.S. naval vessel.
| Actor | Role |
|---|---|
 John WayneJim McLain | Jim McLain |
 Nancy OlsonNancy Vallon | Nancy Vallon |
 James ArnessMal Baxter | Mal Baxter |
 Alan NapierSturak | Sturak |
 Veda Ann BorgMadge | Madge |
 Hans ConriedRobert Henried | Robert Henried |
 Hal BaylorPoke | Poke |
 Gayne WhitmanDr. Gelster | Dr. Gelster |
 Gordon JonesOlaf | Olaf |
 Robert KeysEdwin White | Edwin White |
 John HubbardLt. Cmdr. Clint Grey | Lt. Cmdr. Clint Grey |
 Soo YongMrs. Namaka | Mrs. Namaka |
| PPaul HurstMr. Lexiter | Mr. Lexiter |
 Sarah PaddenMrs. Lexiter | Mrs. Lexiter |