The Dakota Boys are digging down to bedrock gold but when they hit the biggest boulder of the season Dustin is forced to rig a new mechanical solution the Graboid.

The first gold nugget promises a monster payday; Dustin dives into the danger zone, a torrent where the current moves rocks, and a rogue boulder almost costs him his life.

73-year-old Dakota Fred gets married for the fourth time and a landslide upstream threatens to unleash a wall of water that could destroy the dive site and drown the miners.

The Dakota Boys return to McKinley Creek to dive for millions in gold. But the fierce Alaskan winter has destroyed their mining equipment. Their luck changes when Dustin locates the perfect plunge-pool he believes contains a massive pile of nuggets.

Fred's ex-boss, Todd Hoffman, has invested $50,000 in the Dakota Boy's operation and makes a surprise visit in a chopper.

A flash flood racing down McKinley Creek threatens to kill the crew and destroy their operation, but the Dakota Boys still manage to find more gold than they've got all season.

'The Dakota Boys' launch their gold dredge. Fred dives in the raging white water, and despite running out of air, the 72-year-old veteran succeeds in finding their first gold.

The Dakota Boys' desperate bid to hit bedrock gold is thwarted when 73-year-old Fred's heating system fails mid-dive and he's is overcome by the glacial Alaskan water.