Nome Harbor's gold-rich ground is nearly depleted driving the crews to prospect far up and down the coast. Zeke makes plans to take partner Emily and their newly built dredge to the notoriously creepy Sledge Island hoping a jackpot of gold exists in the surrounding waters. Meanwhile, Shawn is still confident that the Bluff holds the key to fulfilling his dream of completing work on the mega-barge. Over on the Reaper, Kris Kelly anoints himself head of the family business but his father and brother exhibit skepticism.
Zeke and Emily set off on a prospecting trip in uncharted waters off the coast of Sledge Island. On the Reaper, Kris is dismayed to discover the claim he was going to lease is being confiscated by the government and no one else in town is willing to work with him. Meanwhile, Shawn is determined to find an old mining landmark that will let him know where to set his dredge.
Shawn questions his own judgment after a risky dive nearly ends in tragedy while Zeke spends too much time in deep water and his body pays the price. Meanwhile, the Kellys leave the open water to check out a claim on a distant river but Kris is having trouble locating the exact spot.
George goes against brother Dave's directive not to dive while he's away and Shawn Pomrenke is out of commission with a crippling back injury. On the Reaper, Brad and Andy are frustrated with their captain and consider leaving the operation but Kris makes a deal that could change their luck.
Panic mounts when George is unable to communicate as he attempts to unclog his hose on a dive for gold. Meanwhile, Zeke and Emily try to salvage their dismal season by prospecting near the mouth of a river and Shawn is back at the Bluff confident his crew can find the spot he suspects houses a huge honey hole.
Zeke decides to dive alone in a river but soon finds himself in a potentially life-threatening situation while the Kellys navigate the Reaper through dangerous waters in a desperate attempt to save their season.
Emily tries to save Zeke when a fire breaks out on their dredge and George Young enlists his son to dive while on leave from the military. On the Reaper, Kris weathers a storm of bad luck to score a deal with an Irish claim owner only to find his demands stifling.
Shawn struggles with back problems but the crew is ready to dive in his place if only they could see in the cloudy waters. On Hastings Creek, Zeke faces a dangerous situation involving Emily just as he gets on the gold while George takes stock of his greenhorn season mining in Alaska.
The harbor is starting to freeze meaning the Kellys have just one more day to score big gold and prove their worth to the claim owner. On the Bluff, Shawn's crew battles poor visibility which threatens to derail Mr. Gold's plan prove the location is loaded with gold while Zeke and Emily take dangerous risks in their race to finish the season in the black.