As the cinematic narrative unfolds in Perth, a catastrophic timeline is set into motion. Just ten minutes following a devastating asteroid impact in the North Atlantic, Western Australia is perilously close to being consumed by an apocalyptic firestorm. Within this dire landscape, James and his partner, Zoe, cherish a bittersweet moment at her beach house, where Zoe reveals her pregnancy with James' child. Yet, as the weight of impending doom closes in on him, James grapples with overwhelming despair, channeling his frustrations towards Zoe and deciding to escape to a party he believes to be "the party of a lifetime."
His plans, however, are soon thwarted when he stumbles upon two men who have taken a young girl named Rose captive. Guided by his moral compass, James confronts the captors, resulting in their demise as he rescues Rose, who shares that she got separated from her father in Malaga on her way to her aunt's home in Roleystone. As James navigates the chaos of the world collapsing around them, he desperately seeks to reunite Rose with her father or find another caregiver, only to face heartbreaking setbacks at each turn.
Ultimately, James acknowledges the grim realities they face and decides to bring Rose along to the party. The gathering is a bizarre spectacle filled with reckless games of Russian roulette and escalating promiscuity within the house. Rose, visibly uneasy among the chaos, yearns for an escape, while James finds solace in conversations with Freddy, the party host, whose sister Vicki is James' girlfriend.
In a poignant twist to their earlier exchange, James attempts to share his heavy heart with Vicki, only to be met with her accusatory remarks that deepen his emotional turmoil. It becomes increasingly clear that Vicki has been in denial about the impending apocalypse, and Freddy's bunker beneath his garage starkly highlights the dire truth they all face.
As James comes to terms with his own mortality, he begins to accept his fate, focusing on the urgent task of reuniting Rose with her family. As the night progresses, a disheveled woman arrives, claiming Rose is her long-lost daughter, Mandy, heightening the tension. Rushing to find Rose amid the chaotic festivities, James instead discovers her in distress due to an ecstasy pill she was given. The woman's frantic insistence that Rose was kidnapped exacerbates the anxiety of the situation, and just as Freddy confronts James, holding a gun with intentions to harm, Vicki steps in, swiftly ending the woman's claims with a precise shot.
James makes a hurried escape from the chaos with Rose, mindful of her fragile state. Their journey leads them to James' estranged mother's home, where reconciliation and solace are offered. His mother provides essential supplies for their travel and a change of clothes for Rose before they set off to find her aunt. Upon arrival, however, despair shatters their hopes: Rose's family, including her father, is discovered lifeless, scattered across the scene like tragic remnants of a once-vibrant life. Rose’s agony at her father’s death rings painfully true, yet she insists on paying respects to the fallen. Together, in a tender moment by the pond surrounded by flowers, Rose urges James to mend his relationship with Zoe.
Motivated by her words, James rushes back to make amends with Zoe, only to become ensnared in traffic as the inferno looms in the distance. With time slipping away, James pushes forward with desperation. Eventually, he finds Zoe on the beach, where her initial anger melts into deep sadness. As they reconcile and profess their love for each other, the approaching flames paint a haunting backdrop to their renewed passion. In a heartfelt embrace, they turn towards the encroaching firestorm, ready to face the tumultuous fate awaiting them.
