Tarzan and the Beast in the Iron Mask

Tarzan and N'kima prepare for a celebration held by the Wazdon Chief Denat in the lost land of Paludon. Upon arrival, he sees that Denat isn't himself and flees the guards. When he infiltrates the tower, he finds a man in an iron mask who is the real Denat and that his evil brother Tanat has assumed his identity and has been having the tribesmen mine for gold in a volcano. Now Tarzan must find the key to the mask which is guarded by a Dimetrodon, free Denat, and help Denat expose Tanat's plot.