They found themselves in a prehistoric land-thousands of miles underground.

When David Innes and his inventor friend pierced the crust of the planet earth in their fresh burrowing gadget, they broke right into a strange new inner globe of eternal daylight where prehistoric monsters still lived and cave men and women battled against cruel, inhuman masters.

The storyplot of what both of these men did in that new world of Pellucidar makes At the Earth’s Core among Burroughs’ most outstanding bestsellers.