Plunging hundreds of feet below ground, Josh explores Spain's treacherous La Garma cave system and finds a floor littered with human remains more than 1,000 years old; Josh's deep dive is a quest for scientific proof of Spain's legendary King Pelayo.

A clandestine meeting with a Cambodian looter puts Josh on the trail of multi-million-dollar stolen monuments; Josh dives into a murky moat, where he unearths a priceless lost statue and a missing piece of a national treasure.