At the Earth's Core

On its very first run, Abner Perry's iron mole bores five hundred miles straight down and breaks through into Pellucidar, a hidden world inside the Earth where the sun never moves. Time hardly seems to pass there. David Innes and Perry climb out among cave men and beasts from the planet's childhood.

Within hours they are chained in a slave line, driven by gorilla-like Sagoths to Phutra, city of the Mahars: winged reptiles that rule the inner world and treat humans as cattle. David makes allies like Ghak the Hairy One and enemies like Hooja the Sly One. He also offends Dian the Beautiful without knowing how, and sets out to make it right.