The Bushmen battle to break through into an abandoned mine. The Young Guns face equipment failure 800km from home.
The Blacklighters plan for a massive open cut mine pushes their machines to the limit. The Young Guns leave White Cliffs to mine in Lightning Ridge.
The Bushmen gamble the rest of their retirement fund on a new drill. The Cheals face off against turbulent weather to rescue their season.
The Taranto brothers risk man and machine moving their entire operation and the Blacklighters win a dugout at auction but get more than they bargained for.
A mountain of mine-waste rains down on the Blacklighters, threatening their operation. The Mooka boys head for a abandoned mineshaft believed to be full of cut opal.
The search for deep opal forces the Bishop to blow the Cathedral sky high and the Cheals race against the clock desperate to hit rare black opal.
Australia's toughest treasure hunters are back, taking on the extreme hardship of the Australian outback in pursuit of opal riches.
The Blacklighters are forced to move Opalzilla to a new claim and the Cheals face season-ending engine failure.
The Misfits search for a new claim in perilous opal fields the Taranto brothers strive to fulfil their family legacy by mining on hallowed ground.
The Bishop invests in a mammoth new claim and the Tunnel Rats operate their one tonne digger for the first time.