[4] The film takes place in Perth and begins ten minutes after an asteroid has collided with earth in the North Atlantic, leaving approximately twelve hours until the subsequent global firestorm reaches Western Australia.

The girl, named Rose, explains that she was separated from her father in Malaga en route to her aunt's house in Roleystone.

Upon arriving, he finds his sister and her husband dead in the shower and three crosses marking what appear to be his nieces' graves in what is an apparent murder suicide.

In a reversal of the earlier scene with Zoe, James attempts to share a serious moment with Vicki, only for her to berate him for bringing her down with his news.

When James finally comes back outside to find Rose, she is hallucinating and vomiting after being coerced into taking an ecstasy pill, with the woman leaning over her.

Upon arrival, nobody seems to be home, but James finds the bodies of Rose's family, including her father, outside in what seems to be a mass suicide.

James comforts her and brings her his body, and they lay him by a pond with flowers as she tells him that her dad wanted them to be together for the end.

The critical consensus states: "Writer-director Zak Hilditch's thought-provoking screenplay – and a stellar performance from young Angourie Rice -- make These Final Hours worth watching, even if its end-of-the-world premise is overly familiar.