A lack of water sends Max and Glenn out into the wilderness to hunt sapphires; Anthony and Jodie take a massive wrong turn underground; the Richardsons' big machines bring on big problems.

Todd and Brianna must navigate parenthood and sapphire hunting; Old Timers Ray and Paul might be digging in the wrong spot; Max and Glenn bring in the drillers, but they risk striking water.

Rowan drills up a lot more than he bargained for; Anthony and Jodie Mifsud desperately attempt to join tunnels; Old Timers Ray and Paul realise too late that an old mine conceals a deadly secret.

The Mifsuds hope their sons will make a difference, but it may cost them a sapphire; Ray and Paul come unstuck with a 40-tonne drill.

Storms hit the Gemfields and Max fights his way to the lease, but the floods might have destroyed his dam; Todd and Brianna face destruction at the claim; Rowan Richardson must act fast to save the mine.

Max and Glenn think they've caught a break when water returns to the dam, until their machines break down; Todd and Brianna must deal with a phobia and an unsafe situation; the Mifsuds' season is interrupted by a family feud.