Edgar Rice Burroughs' Tarzan #39

In the heart of the lost world of Pal-ul-don, Tarzan ventures into the perilous Valley of Monsters, where he rescues Ro-Mee-Lah, sister of his ally Jo-Rah, from the twisted tribesmen of Monga. Armed with a mysterious dyal from Jo-Rah, Tarzan faces the jungle’s strangest dangers as he fights to survive and uncover the secrets of this ancient realm.

In "The Elephants of Athne," Tarzan arrives in the mysterious city of New Athne only to find two archaeologists imprisoned by Prince Ergon, who demands a rifle and a safari car as ransom. When Tarzan returns with the requested items, he’s surprised to learn the captives have no desire to leave—they’ve grown eager to continue their study of the ancient city.

In the heart of the African jungle, Dan-El and Natongo stumble upon the hidden kingdom of the Aba-Zulus, where a mysterious key and a birthmark unlock a long-forgotten claim to the throne. As the king’s speaker, Kongoni, recognizes Dan-El’s lineage, the brothers must vanish into the night, their fate hanging in the balance.