While using a large mining device, two men, David Innes and Abner Perry, are transported into a lush prehistoric land hidden beneath the Earth's crust. They are both captured and forced to participate in its brutal practices. David Innes and Abner Perry use a large mechanical prospector to mine the Earth's surface. When the machine malfunctions, they lose control and are transported deep into the planet's core. Instead of boiling lava, they're met with a tropical paradise occupied by foreign creatures and stone-age men and women. The humans are enslaved by a reptilian species, forcing David and Abnery into bondage. Despite their circumstance, they join forces to create a plan to abolish the hierarchy, once and for all. At the Earth's Core combines the most popular elements of science fiction and fantasy. Mystical creatures and time travel are a large part of this colorful tale. It's another example of the strong visual style Edgar Rice Burroughs is known for.