Since the dawn of civilization, humanity has been fixated on predictions of the end times and our own demise. So, what can we learn to prevent existential threats to the survival of mankind? Will nuclear disasters similar to Chernobyl cause widespread destruction in the future? Or will it be a rampant disease like the Black Death that brings our entire civilization to its knees? Perhaps a massive tsunami will swallow entire regions, or a super volcano will rain fire and devastation throughout the globe. Can mankind avoid the end of days?

For centuries, mankind has wondered what lies hidden in the depths of the Earth. For instance, what military secrets do underground bases like Area 51 and the Cheyenne Mountain Complex hold? And can discoveries in tunnels from the ancient past--like the Tayos Caves of Peru and the Longyou Caves of China--illuminate the cultures of lost civilizations? As humanity develops and digs further into the Earth, including the search for rare elements, what else will we uncover?