Corporal Larry Grant and Sergeant "Mac" McGowan, of the United States Marine Corps, are rival for the love of Frances Schiller, but team up to hunt down "The Tiger Shark," a mad, scientific wizard who is holding Sergeant William Schiller, Frances' brother, a prisoner on a wild, jungle island in the Pacific.

Grant Withers
as Cpl. Larry Lawrernce

Adrian Morris
as Sgt. Mack McGowan

Ann Rutherford
as Frances Schiller

Robert Warwick
as Col. W. R. Bennett

George J. Lewis
as Sgt. William Schiller [Chs. 1-4]

Pat O'Malley
as Capt. Grayson [Ch. 1]

Victor Potel
as Fake Native Chief [Ch. 12]

Jason Robards Sr.
as Kota

Warner Richmond
as Metcalf

Robert Frazer
as H.R. Douglas