Tarzan once again returns to Opar, the source of the gold for lost colony of fabled Atlantis. Ever since Atlantis sank beneath the waves, the workers of Opar have continued to mine all that gold, which means there is a rather impressive stockpile. Tarzan follows a greedy Belgian and Arab into the jungle, where the evil pair manage to stumble upon the lost city, at which point our hero loses his memory after a fight. This is good news for La, the beautiful high priestess who serves the Flaming God, because she has had that big crush on the ape man since their first encounter. Meanwhile, Jane is in trouble back at their African homestead and wondering what is keeping her noble husband from once again rescuing her.