Typical of an Edgar Rice Burroughs fantasy adventure, nudity abounds in At the Earth's Core, with women and men stripped to the waist. Shapely, athletic men and women in scanty attire is common in sword-and-sorcery adventures, and young adults who have read Burroughs's other novels or those of authors such as Robert E. Howard or L. Sprague de Camp are likely to be familiar with the customary bare-breasted women. The graceful sensuality of Dian and others is never the focus of the story but is instead just part of the setting—an essential feature of the background that makes Pellucidar an exotic, exciting place for heroic adventure.

Perhaps more worrisome are the scenes of torture and brutality, although they always promote one or more of the chief ideas of the novel.

The vivisection scene in which Mahars dissect conscious human beings reflects an issue that...