A sea captain about to be hanged for a murder he didn't commit is rescued from the gallows by two of his crewmen. They head for the island of Pulinan, where they believe the real murderer--the captain's former partner--is hiding so the captain can clear his name. As it turns out, their troubles are only beginning.

White Eagle was raised by Indians after his father, a US army officer, was killed in an Indian raid. He believes that the Indians and the white settlers can live together and works towards that goal, but a gang leader who has his own reasons for not wanting peace between the two groups sets out to stir up as much trouble between them as he can.

Walter Calvert (Davison Clark) calls upon his brother Henry (Davison Clark) at his eerie old house and demands a share of the family fortune, and threatens to kill Henry if he doesn't get it. A few days later Henry's car goes over a cliff and he is presumed dead. Bob Stewart (Robert Kent, a detective whom Henry asked to investigate the matter if he should die, starts his investigation and Duke Ellis(Tim Ryan, a newspaper reporter friend is with him. Bob meets the family at their mansion and questions Henry's sister, his half-brother, his nephew and his nephew's bride, and Ruth Allen (Amelita Ward), whose father was in business with Henry. Henry's brother Patton (Charles Middleton) and a shadowy figure known as The Voice (NO, not the Narrator)plan to kill all the relatives and divide the fortune. As the murder attempts multiply, Bob, Ruth and Duke endeavor to track down the masterminds and bring them to justice.

Larry Munro has discovered a vein of platinum on his ranch. A group known as the Secret Seven has learned about it and plan to get the Munro Ranch. Kentucky Wade and his friends arrive to help Larry and are soon fighting off attempts on their lives by the henchman of the Secret Seven and the Indians they enlist by bribing them with rifles.

An expedition arrives on an uncharted jungle island to rescue the local natives, led by a jungle boy, from a volcano that is about to erupt.