With an access tunnel to the underground cavern finally opened, and a tantalizing clue discovered, Duane's son Chad takes a risky dive into the flooded cave system -- and what he finds defies all explanation.
Duane decides that the flooded cave is too dangerous to dive into again, forcing the team to explore new access points to the underground cavern system. But something lurking in the darkness forces everyone to reevaluate their safety.
While searching unexplored areas of the ranch for an alternate entrance to the cavern system, the team discovers mysterious ancient markings on a cliffside and a mining shaft dug deep into the mountain that could lead them right to the gold.
Duane employs ground-penetrating radar to scan the land near a potential drill site, leading to a mysterious finding. Trespassers prompt Charlie to increase security on the ranch with a camera system -- capturing a frightening sight in the dead of night.
As winter closes in and the digging season nears its end, Duane takes a final shot at getting into the underground cavern ... but uncovers a whole new mystery about the land he owns.
