Danger and Mystery at the Earth's Core. David Innes, discoverer of the Inner World of Pellucidar, had carved out his own empire among the cavemen there. He had set out on an exploration of new territories-and disappeared. A rescue expedition under the leadership of his cavewoman queen, Dian the Beautiful, began a desperate search for him-only to plunge them both into an ordeal of incredible danger.

Genre: Science Fiction