From the back of the book:
A lost civilization in need of a miracle. A frozen city harboring a terrifying secret. An ancient legacy best left undisturbed. A crime lord determined to conquer a hemisphere.
Hollow Earth Expedition: Perils of the Surface World compiles four adventure scenarios that span the globe and deliver a walloping punch of pulp-era adventure. Your characters will battle Nazis in the tropical jungles of Brazil, unearth monsters in the frigid wastes of Antarctica, unravel mysteries in the catacombs beneath Venice, and contend with martial arts masters in the back alleys of Shanghai. Each of these scenarios can stand alone or may be added into existing campaigns, linked together with each other, or used to open the way to further adventures inside the Hollow Earth.
Perils of the Surface World also delivers new resources for the Gamemaster, including optional rules for martial arts super-powers, Atlantean sorcery, supernatural terror, and more. Add these tools to your kit to adapt and expand your adventures and your characters in these or your own stories!
Strap on your holster, grab your fedora, and get ready for two-fisted pulp adventure!