After skipping town a decade ago, transgender activist Caz Davis returns to the remote, politically divided dairy community of Rurangi, hoping to reconnect with his estranged father, who hasn't heard from him since before Caz transitioned.

Tatau follows Kyle and Budgie, two twenty-something friends from London that set off to travel the world. Ahead of the journey, Kyle gets a Maori-style tattoo to celebrate their eventual destination: the Cook Islands. When snorkeling in a lagoon, Kyle finds the dead body of a local girl, Aumea, tied up underwater. Returning to the lagoon with the police, Kyle finds her corpse has disappeared. But Kyle knows what he saw. Desperate to uncover what happened, Kyle and Budgie find themselves sucked deeper and deeper into a world of Maori myths, symbols, and hallucinatory visions... until finally the full meaning of Kyle’s tattoo is revealed.

The Dark Horse is an emotionally-charged and inspiring drama about a man who searches for the courage to lead, despite his own adversities - finding purpose and hope in passing on his gift to the children in his community.

Burnt-out trans activist Caz returns to the rural dairy community he fled before transition, to reconnect with his father. As father and son reconcile, Caz finds new purpose, spearheading the town's environmental fight against 'Big Dairy'.