This is the second edition of The Hollow Earth, which was replaced in 2018 by a new, third edtion that fits with Rucker's sequel, Return to the Hollow Earth.
In 1836, Mason Algiers Reynolds leaves his family's Virginia farm with his father's slave, a dog, and a mule. Branded a murderer, he finds sanctuary with his hero, Edgar Allan Poe, and together they embark on an extraordinary expedition to the South Pole, and the entrance to the Hollow Earth. It is there, at the center of the world, where strange physics, strange people, and stranger creatures abound, that their bizarre adventures truly begin.
