The Young Guns' season is threatened when JC is injured at a steer riding competition. The Bushmen finally strike opal while digging on the boundary of their claim;. The Cheal's struggle to get to their claim after weeks of rain.

The Blacklighters run into devastating mechanical problems; the Opal Whisperers show there's big money to be made hunting a rare form of opal.

Rory and Oscar are forced to operate their dad's 20-tonne drill rig for the first time. The Tarantos are struck down by sickness as they struggle to find Opals on their massive claim, and the Bushmen build a dangerous mine roof.

The Tunnel Rats risk their lives to get a massive digger under the ground, hoping it will pay off. Meanwhile, the Blacklighters are amazed to unearth the largest piece of opal they have ever found.

The Bushmen's new worker faces a dangerous first day on the job. The Tarantos' overworked excavator grinds to a halt, and the Cheals are hit with more breakdowns in their search for Opal.

The Bishop mines the support pillars in a mammoth new claim and the Tunnel Rats risk electrocution while using their one-tonne digger to mine for crystal opal. The Misfits hunt for Andamooka opal in isolated mines in South Australia.