Tensions spill over as the Poseidon Crew face a series of breakdowns, the Ferals are kicked off gold-rich ground before a new lease turns up a major haul, and the Gold Timers get lost in the outback.

The Poseidon Crew's research digs up an old treasure map that leads to the biggest nugget of the season; Marcus and Linden call in a mentor to help get them on gold in the first week of the season.

Roy battles hazardous loads and a terrifying brake failure, and Chevy fights worsening weather and an oil leak on his first solo haul.

The Goldtimers catch a gold thief, Levi and Bridget make a rookie mistake that could end in disaster, and the Poseidon Crew take a desperate gamble on gold ground they've already detected.

As the wet season looms, the bull catchers race to make money; unflappable Kurt finally meets an obstacle he can't sidestep when his buyer falls through, and Clarry is nearly ready for retirement.

Myles has a deckhand decision to make. Bryce rockets up the tally-board and Squizzy heads to the casino in the sea.

Tragedy strikes as an earthquake wipes out a building full of people in Christchurch in New Zealand; experts investigate an inadequate structural design and weakness in critical supporting columns.

Andrew and Jeff discover a hidden cave in search of clues and an unexpected find that injects the team with fresh hope.

Disaster strikes when a would-be thief crashes the Desert Diggers' loader; Shane and Rusty drag their dry blower across treacherous ground; Jacqui and Andrew recruit a new prospector to their team.

A mechanical failure puts Brent's son Cayden to the test, a fuel theft grinds the Mackies' operation to a halt, and the Wanderers race to secure a crucial gold deal before a week's end.

Mike pulls a 1941 Ford Super DeLuxe 2-Door Coupe from his 'field of dreams' so he can create a classic beach cruiser, and the crew attempt to restore a '64 Ford Fairlane to its former glory.

Big Al's health takes a hit while searching for new ground.

The Victoria Diggers may have stumbled on a million-dollar motherlode, the Scrappers are at breaking point, and Dirt Dog Jake and his new recruits are urgently trying to supersize their operation.

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.

When a load of dangerous goods sails in, a rookie operator is tested with the offload; meanwhile, a family of fishermen hook the ultimate catch.

Diehard's Michael and Cherie head out to their neglected surface claim to try their luck, and Ray and Paul's trusty old drill rig has blown its engine and the only option is to completely replace it.

Big Al's health takes a hit while searching for new ground.

Marcus, Linden and Dale desperately need new ground, the Poseidon Crew's hope for a 1000-ounce nugget is slipping through their fingers, and Shane and Russell take the biggest gamble of the season.

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.

In Colorado, engineers battle drought, extreme weather and immense water pressure to raise a 70-year-old dam to record-breaking heights.

As the gruelling lobster season enters its make-or-break final weeks, Kevin cripples his boat in a maze of tangled gear, and William relies on an older rookie deckhand seeking healing on the water.

Discover Brazil's largest bank raid - where a gang used an elaborate tunnel to steal millions - and the chilling campaign of the Unabomber whose mail bombs terrorised the US.

After a brutal year of pain and pushing through, Dale pins his hopes on a life-changing surgery while Gripp steps up to carry the load.

It's almost the end of the mining season, and with water in the dam, Max and Glenn may finally get a break, but Todd and Brianna need a big haul of sapphires to keep them in business for the summer.

Orca research, ancient K'ómoks fish traps, and a salmon hatchery - on BC's coast, the past is teaching the future how to survive.