Within the treacherous caves of Undara, a betrayal will test the bonds of friendship and family.

When entomologist Emlyn Rees arrives at Hidden Valley, she wants nothing more than to escape her marriage breakdown by burying herself in the research team's hunt for new species of insects in the depths of the dramatic Undara lava tubes. Little does she suspect she will be the key to solving a mystery that's more than one hundred years old.

Travis Carlyle is initially resistant to letting some city academics tramp over his cattle station. Still, soon, the researchers' findings and a growing friendship with Emlyn bring opportunities to turn around his struggling farm. With a broken marriage behind him and children to care for, Travis needs to plan for the future, and this could be his family's best chance.

But when things start going wrong for the farm and around the dig site, Emlyn and Travis are at a loss to understand why. Are they cursed with bad luck, or is there a more sinister force at play? Are the tall tales of enigmatic stockman, Bluey true? As the unseen saboteur grows bolder, Emlyn and Travis are caught in a race against time to save the station ... and their lives.