Abner Perry's new prospecting vessel, which is powerful enough to push through solid rock like a submarine through water, is certain to revolutionize mining. Young mining heir David Innes eagerly backed the invention and now joins Perry on the vessel's maiden voyage. But as they descend, they discover with horror that they can't steer through the subterranean rock. Desolate, they await suffocation deep inside the unforgiving earth.

At the last moment, however, the vessel surfaces. After encountering a prehistoric monster and some long-tailed, manlike apes, Perry and Innes wonder where on Earth they could be. When Perry notices the sun hasn't moved in hours, he realizes there's only one conclusion: The Earth is hollow and they're inside, on an inner surface warmed by a miniature sun at the very core.

The true humans of this lush, raw domain are enslaved by the Mahars, a wise but sadistic race of great flying lizards. Soon the visitors are captured and taken in chains to a Mahar city. Next to Innes on the chain is a proud native woman, Dian the Beautiful, who spurns Innes, then escapes. Meanwhile Innes and Perry learn the Mahars are an all-female race, preserved by a secret egg fertilization formula. Stealing the formula would end Mahar mastery over this strange world, called Pellucidar.

Before that can happen, however, a rampaging monster causes chaos in the Mahar amphitheater, and Innes escapes. After a series of adventures with the island king, Ja, Innes returns to steal the Mahar secret formula. The plan succeeds, but in drawing off pursuit Innes becomes separated. He wanders far, confronting huge creatures, hostile natives and Dian, who still professes to hate him. Innes faces life alone as a dinosaur-hunting caveman in the prehistoric world at the Earth's core.

The land that physics forgot

At the Earth's Core is one of those red-blooded adventure stories in which the men are a real men and the women are real women, in that order. Strapping young millionaire David Innes falls down the rabbit hole--with the help of an older, less strapping inventor whom he keeps losing track of--and once there he slays dragons, saves the world and wins the heart of the beautiful but haughty princess. On that level it's a vital, well-told story with an interesting hero. Also it's an intriguing sketch of native human cultures under the thumb of overlords more alien than evil.

But there's a little more to it. At the Earth's Core, like much of Burroughs's work, can be read as an allegorical commentary on the degeneration of civilized society. The humans of Pellucidar are represented as physical ideals with, in general, superior moral strength. Innes explicitly compares Dian to the perfidious outer-crust women he left behind. Burroughs's point about humanity having lost virtue through progress and the trappings of modern society rings even more true in the year 2000 than it may have in 1922.

Both this edition's introduction, from peerless scientist-author Gregory Benford, and the scholarly afterword reject the plausibility of the inner world Burroughs described and tried to justify. While this is nice to know--readers may well be curious on this point--it doesn't really matter. At the Earth's Core is fantasy and pulp fiction; saying Pellucidar couldn't exist is like saying the same of J.R.R. Tolkien's Middle Earth or the rampaging planets of When Worlds Collide. As with E.E. Smith and other early pulp SF writers, action, adrenaline and--with luck--internal consistency are all readers should expect. On that count, At the Earth's Core delivers.