History is made as one team unearths the biggest gold nugget ever found by the Aussie Gold Hunters; the Gold Gypsies get their excavator back from repairs; Greg and Chris hit a patch of gold nuggets.

The Gypsies are on gold before thieves raid their nearby lease, the Scrappers' struggles go from bad to worse, and the Dirt Dogs urgently need the mill to keep running daily for the next three months.

The Victoria Diggers' million-dollar dream is at breaking point, the Dirt Dogs hunt down gold thieves, and the Mahoneys stumble across a mysterious murder.

The Victoria Diggers' fight for survival could deliver a monster nugget, and the Gold Gypsies fend off deadly snakes as they strive to keep their gold dream alive.

In Liverpool, engineers battle unstable ground, wartime hazards and fierce waterfront winds to build a 52,000-seat stadium on a former dock in record time.

In Germany, engineers battle groundwater, tight space and complex logistics to build Frankfurt Airport's Terminal 3 - a vast new mega hub designed to handle 19 million passengers a year.

In the Netherlands, engineers race to build Hawaikinui 2 - a next-generation cargo ship designed to supply some of the most remote islands in the South Pacific.

In France and Italy, engineers battle crushing rock pressure, unstable geology and extreme underground conditions to build the longest railway tunnel ever constructed beneath the Alps.

In Greece, engineers battle earthquakes, unstable ground and coastal winds to build the country's first true skyscraper on the shores of the Mediterranean.

When Bruce learns his mum has had a stroke, he and Juanita rush to her side leaving Tiger and Tom in charge; with the season's fate hanging in the balance, the crew finally reach the Cape.

Juanita goes missing at Cape Carnage and Bruce disembarks; Tiger decides to go to Karumba to unload as tides worsen, but his plan backfires and the Wildcard is forced into a U-turn.

The Wildcard crew pushes hard to hit their 35-tonne season break even target, and a return to Cape Carnage results in a season-ending injury.

The Wildcard crew battles sharks, a giant crocodile, a chronic injury, arguments and persistent fog that all threaten to derail reaching their season target.

In their final week, the Wildcard crew is more than two tonnes short of their 65-tonne goal; with sharks circling at Cape Carnage, they fight for their last chance at a killer catch.

Jacqui and Andrews' big gold dreams are stalled by communication issues, and the Poseidon Crew battle wet weather to unearth a monster pay day.

An armed trespasser threatens the Gold Devils' exploration mission, and the Ferals uncover the biggest gold nugget of their mining careers.

The new team of Alan and Salty take the plunge in search of underwater nuggets, and the Ferals hit a rich patch but are forced to chase away thieves.

Shane uses a clever bush fix to get himself out of a jam in the remote outback, and the Gold Retrievers find a gold-rich quartz vein that could hold the motherlode.

The Poseidon Crew battle challenging terrain in the mountains of High Country Victoria, and promising signs could lead the Gold Devils to a million-dollar pay day.

Winter planning begins to fall apart for Alaskans as they prepare for the impending freeze.

Sue Aikens returns to find a dangerous predator lurking just outside of camp. Meanwhile, the lake outside of Glenn's cabin is frozen, so the conditions are perfect for finding goose grass.

A risky halibut haul, life-saving training, and a heroic air rescue push crews to their limits.

Fishers and divers search for prized species while researchers fight to prevent a brutal invasion.

A deep dive for Second World War history tests divers, and a fisherman faces a surprise Fisheries and Oceans Canada (DFO) inspection at sea.