Todd gets a jump on next season by shipping his best wash plant to Alaska.
As melting permafrost makes mud out of pay dirt, Andy devises an engineering longshot to prove the Lost Cut is rich with gold. As Todd and his crew dial in the wash plants, anticipation grows for what could be the Hoffmans' biggest gold weigh of all time.
Hunter treks into the tundra to prospect for new paydirt before the Lost Cut runs dry. Todd secretly ships Jack's 1980s-era washplant to Alaska to fulfill his dad's original gold-mining dream, but reassembling heavy steel on-site brings its own surprises.
The Hoffmans are succeeding on an Alaskan mine site that ruined generations of miners before them. But when muddy meltwater infiltrates their wash plants, Andy must re-engineer their entire water circulation system to keep their gold from floating away.
A shift in the weather turns Andy's routine mining decision into a potential disaster when melting ice threatens to contaminate the nearby creek with silt. Hoping to avoid a million-dollar loss, Todd attempts an engineering solution to help save the mine.
When state inspectors make a surprise visit to the mine, Todd braces for citations and fines. But when it appears the government could shut them down completely, the Hoffman team races to save their operation before the inspectors return with a verdict.
When the government orders a long list of fixes, Todd's crew questions if they can work with little hope of a gold bonus. Frustrations reach a breaking point between Chambo and Andy. For Todd, it comes down to a single gold weigh to keep his crew intact.
As the Hoffman crew completes a marathon of government fixes in record time, Todd promises a gold bonus to everyone who completes the season. When Todd hires new miners to get the plant into operation, one greenhorn struggles with the rigors of the job.
As pay dirt from the Lost Cut Mine runs low, Hunter runs dirt from a promising new location called the Plateau. Framer disappears after heading out on a solo caribou hunt, forcing Todd to turn to the Alaska Troopers for help with the search and rescue.
When the motor in Todd's Black Pearl trommel catches fire, the Hoffman crew attempts to modify the smaller wash plant Jack built decades ago to run more pay dirt. But after Todd orders round-the-clock mining to hit their goal, failures begin to mount.
Ice sets in early, threatening to freeze the operation. In a desperate search for unfrozen ground, Andy creates a novel solution: digging up the road they built at the start of the season to harvest the gold-rich Lost Cut pay dirt it was built from.
Todd's crew races to beat 1,000 ounces and make a profitable final season for Grampa Jack. But with a season-ending snowfall in the forecast, the rich pay dirt they need may be in the last place an old-school miner would ever look.