This sourcebook expands Hollow Earth Expedition to include the mysterious and perilous surface world, filled with dangerous criminals, mad scientists, and dark sorcerers. Become a daredevil pilot, private detective, or wandering hero, exploring exotic locales and thwarting evil plots. Meanwhile, world powers and secret societies vie for control of what may be the most important discovery in all of human history: the Hollow Earth.

Includes: new rules for psychic powers, sorcery and weird science; an expanded vehicle and equipment catalog; and details on secret societies and surface world locations.