 Braving danger from hostile savages called the "Pack Rats", Dr. Tom Reynolds/Ramar of the Jungle (Jon Hall), Professor Howard Ogden (Ray Montgomery) and Nancy Arlington (Anne Gwynne) go into the jungle seeking her father, Dr. Arlington (Kenneth MacDonald), believed to have died in an archaeological expedition. They find him alive and rescue him from a renegade guide. After escaping an attack by savage Bessanos, under the leadership of the guide, who is killed in the fight, Reynolds recovers a golden tablet from the tribe.