The Mooka Boys' hopes of a season-saving pocket of black opal are decimated by a busted starter motor on their dozer, crippling their attack against an impenetrable rock cap shielding the opal level below. Blacklighters Mark and Paul are forced to shift 20,000 tons of waste dirt to make their treacherous mine face safe, while John battles Mines Department red tape after running out of noodle-able dirt at 12 Mile. Oscar sends the Cheals on a critical mission to unearth a rare green-orange gemstone for a potential buyer. At the same time, Chris' fabricating skills are tested to get a second agitator online before the season ends.