TARZAN AT THE EARTH'S CORE A startling radio transmission summoned Tarzan to the savage land of Pellucidar, hidden deep inside the Earth. His challenge? Rescue a kidnapped emperor. But first he was forced to emerge victorious over titanic pterodactyls, fierce snake men, and other demonic creatures who hungered to destroy him. TARZAN THE INVINCIBLE When Tarzan tried to stop some greedy tyrants in Opar, an ancient outpost of Atlantis, he was captured by a merciless band of warrior priests who yearned to sacrifice him on the bloody altars of the Flaming God. It took Tarzan's most magnificent display of nerve, courage, and raw animal power to free himself and vanquish the enemy.