The Poseidon Crew are poised to secure ground that could hold multi-million-dollar nuggets, Jacqui and Andrew venture into north Queensland, and the Ferals take a gamble on a remote island expedition.

Brent Shannon's gold dream lives or dies at a weigh-in, Shane and Russell venture out on a gruelling 3000km expedition, and new team the Gold Retrievers unearth a bumper payday.

Scotty takes on a time-critical job, Glenn blows a tyre in the middle of nowhere, and Jake races 2,000 kilometres to hit a lucrative cattle-load deadline.

Heavy rains in Victoria threaten to shut down the Poseidon Crew, Jacqui and Andrew struggle through 40°C heat in Queensland, and the Goldtimers negotiate a lucrative deal to sell their mining rights.

Record cattle prices and a wet season have turned the outback into a gold mine for bull catchers; husband-and-wife team Liz and Willie Cook are expanding their empire, but with ever-increasing debt.

The race is on to finish crab and scallop fishing with lobster season on the horizon, Cody's crew hauls record catches, and William pushes both his crew and Moonship to breaking point.

Catastrophe strikes a lakeside community in Canada as an oil train explodes in the heart of downtown, and what triggered a massive explosion that devastated a rural town in Nebraska?

Matt and Damo weigh up the two offers they have received for their land at Scratchy Moo, and Donnie and Dennis strike new gold at Swiss Diggings but gold poachers attempt to raid their pit.

The Goldtimers hire a 7-tonne loader in a bid to end their gold drought, the Dust Devils risk running out of water, and Marcus disappears while clifftop detecting.

The Poseidon Crew continue their hunt for bush gold, the Gold Gypsies face one of the biggest decisions of their career, and the Victoria Diggers's perseverance could finally pay off.

Mike battles to finish the Road Runner, trading gets nuts with Big Donny, and the crew help a million-dollar build get to the Detroit Autorama.

Ken and Guillaume's equipment problems mean they are only sluicing half of what they should be, Karl must deal with machine design flaw, and Bernie moves his operation hoping his luck will change.

Crippling permit delays force the Poseidon Crew in search of bush gold to survive, the Gold Gypsies discover a bounty of fine gold, and the Dust Devils' gamble ends in a huge mechanical failure.

Shane and Russell rebuild a wet plant in a bid to rescue their season, the Victoria Diggers are forced to dig a neighbour's lease, and brothers Marcus and Linden are stranded in the Outback.

Snow, ice, and a deadly mountain road push Dale to the edge as he fights to stay in control and keep his business moving forward.

Christian digs down with a 38-tonne excavator to the blue clay layer that Ray hopes will be the key to the team finding a fortune, and Elley and Christian find the biggest piece of gold so far.

Ken and Guillaume's equipment problems mean they are only sluicing half of what they should be, Karl must deal with machine design flaw, and Bernie moves his operation hoping his luck will change.

The Poseidon Crew are forced back onto an old lease in flooded Victoria, Shane and Kate call in help in Western Australia, and Jacqui and Andrew get separated at night in far north Queensland.

Disaster strikes the Gold Devils with just weeks left in their season, the Gold Retrievers put their gold dreams on the line, and Vince, Bibi and Murray take a big risk investing in new machinery.

Irv takes on the restoration of an Escort RS1600i from an owner who had to give it up due to ill health. It turns out to be a much bigger job than he imagines.

Mining buddies Donnie and Ronnie have an explosive break-up that threatens Donnie's dream of owning his own lease; at the 1870 mine, Richie builds a gold room to start sorting out fine gold.

Reza uncovers the mystery of human survival in Oman, one of the driest places on Earth.

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.

Anthony and Jodie want to get back to the serious business of finding sapphires but need to remove a big lump of granite first, and Matt and Amber go into partnership with a local miner.

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.