The search for the afterlife begins in the ancient city of Hierapolis, Turkey, where Gates explores a recent archeological discovery - a portal to the underworld. According to ancient Roman accounts, something within this legendary cave killed every animal that stepped inside, and it's up to Josh to figure out why.

From ancient tombs to the latest technology, humans have always been obsessed with cheating death, the Josh visits a tribe in Indonesia where people live with mummies, finally a Russian cryonics laboratory freezes humans for the future