Duane and Chad Ollinger return to Blind Frog Ranch, armed with cutting-edge tech, to unearth $3 billion in hidden treasure. Shocking new information on the underground tunnel emerges. Claim jumpers invade the property, threatening to derail everything.

When a windstorm ruins visibility in the water, Chad considers a risky blind dive to extract the box. But when intruders are discovered, Duane and his crew realize that time is running out.

Chad makes a huge mistake, derailing the operation to drag the box out of the cavern. But when they pull out some of the box's contents, they are shocked by what they discover.

A hidden cave entrance below a lake could finally lead the team into the Keyhole Chamber. After training in Florida with some of the best cave divers in the world, Chad navigates a deadly maze of flooded tunnels and makes a shocking discovery.

Following the trail of the Lost Rhoades Mine, Chad and Ryan attempt to rappel down a 250-foot cliff in a dangerous maneuver to access the Mormon Eye cave.

While drilling into the cavern system to find the Aztec gold, the team strikes an impenetrable object deep below ground.

Duane recruits treasure hunter Josh Feldman, who recommends a new plan of action to find the Aztec gold. But before they can break ground, a local Timpanogos tribal elder visits the ranch with disturbing words of warning.

Believing they might have drilled into an Aztec aqueduct at the Bead Site, Duane and James head to Mexico to meet an expert. Chad and Josh trace the underground waterway to a remote lake that might be protecting a secret.

After Duane makes a costly mistake, Eric and Chad finally discover what they've been looking for. However, the crew gets caught in the cross hairs of mysterious intruders.

Now that the floodwaters have receded at the Energy Zone, the team prepares to resume drilling into the cavern system.

Eric and Chad encounter disaster while attempting to breach the void in the South Cave. A mysterious rumbling shakes the ranch, and James finds evidence of the Aztecs at the Bead Site.

Chad and Eric find signs of gold at the abandoned mine, but nightfall brings an unwanted stalker to their camp. At the Bead Site, the team unearths an ancient structure.

When an underground tsunami floods the cavern system, Duane and his team attempt to breach it from higher ground -- discovering evidence of Aztec artifacts and a crucial clue to the Lost Rhodes mine.

After uncovering a bar of gold at the Bead Site, Chad and James set out to research where it might have come from. With trespassers still threatening the ranch, their discovery sets them on the path of the fabled Lost Rhodes Mine.

Chad and Eric explore a deep cavern while Duane discovers smoke vents.

After a long winter, the crew returns to Blind Frog Ranch to strategize a new plan to get the box out of the underwater cave. And Charlie asks for help to investigate a mysterious death on the ranch.

Determined to get into the cavern, Duane and his team explore new methods to find a dry entrance; while Chad takes to the skies in search of a natural opening, Eric thinks the radioactive rocks found in the box might show them where to dig.

Searching for the hidden entrance to the cave system, the team uncovers an ancient vent shaft above the Energy Zone. But an explosion triggers an underground tsunami that threatens the cave system.

After hitting a meteorite deep underground while trying to drill into the cavern system, the team searches for an alternate route.

Duane uncovers a whole new mystery about the land he owns.

The results from radiocarbon testing are in, which will tell Duane if the box is Aztec or not. Then, the men discover they are being surveilled by a high-tech camera mounted just above the cave entrance.

Chad and Eric discover an abandoned mine deep in the mountains and suspect they are being stalked. At the Bead Site, the team unearths evidence of sacrifice.

The team catches a break while trying to find a new entrance to the cavern.

After the crew drills into a dry cavern, they must devise a plan to protect themselves from radioactivity and poisonous gasses; but as they get close to finally entering the cave, trespassers descend upon the ranch.

A mystery lurking underground forces the team to reevaluate their safety.