Ava Newman, an American physiotherapist, volunteers for a grim Australian military body retrieval program following a devastating experimental detonation. Driven by unresolved guilt over her fractured marriage, she desperately seeks her missing husband, Mitch, in the restricted southern zones. Abandoning her assigned unit alongside fellow volunteer Clay, Ava navigates a desolate landscape populated by reanimating, single-minded corpses. Her fixation leads her into a tense captivity with Riley, a unhinged soldier harboring a pregnant, reanimated wife. After escaping, Ava pushes onward to her husband's last known location. She confronts the bitter reality of their final days, ultimately forming an uneasy alliance with the shifting environment and Clay to find an impossible sign of life amid the decay.