When two friends wander down a maze of underground tunnels, they stumble upon the entrance to another world populated with a race of advanced humanoid beings. These beautiful subterranean creatures hold immense power in the form of Vril energy, and they've got a plot to conquer the overworld. This 1871 sci-fi novel presents a fascinating story about society, science, and philosophy. A best-seller in its day, this supernatural Victorian travel tale holds its own among the popular dystopian works of today.