John Grant, a mild-mannered schoolteacher, completes his term at a remote school in the Australian Outback. En route to Sydney for Christmas vacation, he stops in the desolate mining town of Bundanyabba, colloquially known as "The Yabba." Intending to spend just one night, he is quickly drawn into the town's aggressive hospitality and unrelenting hedonism. At a local bar, John meets several locals who embody The Yabba's rough spirit, including the eccentric Dr. Tydon. Succumbing to the locals' pressure, John joins a gambling game, only to lose all his money, trapping him in the town with no means of escape.

Stranded and desperate, John becomes entwined with the town's sordid culture, gradually abandoning his civilized demeanor. His attempts to leave are repeatedly thwarted by the town's open-armed yet suffocating social net. He drifts deeper into a vortex of alcohol, violence, and moral degradation, guided by Dr. Tydon and others. John’s psychological descent intensifies as he grapples with his loss of control and deteriorating sanity. What seemed like a brief detour in his travel plans morphs into a relentless nightmare, revealing the underlying menace of the seemingly amiable townspeople and the harshness of the landscape they inhabit.