Filmed in the Sierra Nevada mountains near Sonora, California, this Universal serial is Universal's 40th sound-era serial. Eagle Scout Bruce Scott, leader of Martinsville Troop Number One, and his pack sets off in search of lost treasure and finds adventure.

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.

A scientist invents a poison gas; the villain and his gang will do anything to get the formula; our hero, "Lightning Hutch", is sent to save the scientist, the scientist's beautiful daughter, and the formula.