Synopsis by Hans J. Wollstein
In chapter four of The Mystery Trooper, Chief Red Eagle (William Bertram) manages to free himself and warn Billy (Buzz Barton) away from the booby-trapped door. Jack Logan (Robert Frazer), meanwhile, recovers the stolen map from one of the henchmen. With Red Eagle as their guide, Jack, Helen (Blanche Mehaffey) and Billy locate a letter stating that the other half of the map to the hidden mine may be found "under a stone serpent in the Cave of the Sacred Dance." Trailed by Mack (Charles King) and his thugs, our friends enter the cave only to find it occupied already by the increasingly irate grizzly bear. Original chapter title: " The Cave of Horror."