Z for Zachariah (2015)

Z for Zachariah is a 2015 science fiction drama film, based on the book of the same name by Robert C. O'Brien, directed by Craig Zobel and written by Nissar Modi. The film stars Margot Robbie, Chiwetel Ejiofor, and Chris Pine. The film was released on August 28, 2015, in the United States by Roadside Attractions.

Nuclear apocalypse survivor Ann Burden seeks out an agrarian life on her family's valley farmstead, sheltered from radioactive contaminants by rocky hillsides, favorable weather patterns, and an abundant ground-fed water supply. One day Ann encounters fellow survivor John Loomis, a highly skilled engineer, who, aided by medicines and a radiation suit, has travelled from a distant military bunker to the safe confines of Burden's valley. Loomis bathes in contaminated water, and immediately sickens, but is nursed back to health by Ann, who welcomes him into her farmhouse.

Loomis regains his strength and gradually becomes part of Ann's humble rustic life. He helps Ann to pump gasoline from local petroleum pumps and gets the farm's long-disused tractor running, hoping to stockpile food for the winter. Ann tells Loomis about her parents and younger brother who left the valley to find other survivors but never returned. Loomis speculates that hydroelectric power might be generated from the nearby waterfall, using a water-wheel fashioned from the Burden church's planks and beams. Ann is uncomfortable with this proposal, citing her father's past involvement as preacher and her own deeply-held Christian beliefs. Loomis chooses not to pursue the project further.

Ann and Loomis grow closer, cultivating crops and preparing for long-term habitation. Their domestic accord is marred by occasional tensions, notably involving matters of religion and Loomis' drinking. The two come to the verge of initiating a sexual relationship, but Loomis demurs, stating that further intimacy will change things between them, and that more time is needed.

Mysterious phenomena (including stolen food supplies and a half-glimpsed shadowy figure) culminate in the arrival of a third survivor, Caleb. Though Ann welcomes Caleb into the farmhouse, friction develops between Caleb and Loomis. Loomis questions Caleb's backstory and motives; Caleb repeatedly emphasizes the religious connection he shares with Ann (in stark contrast to Loomis), and suggests a light-hearted wager for the farm-girl's affections while the two men go out turkey hunting.

The three survivors slowly settle into a marginally-stable partnership. Both men relate post-apocalyptic horrors they witnessed before reaching the valley; Loomis describes a radiation-sickened youth who begged him for death, later privately confiding his belief that the dying boy was Ann's long-absent brother. Caleb pressures Ann to go forward with the water-wheel project, and work commences on tearing down the church for materials. Perceiving their mutual attraction, Loomis awkwardly gives Ann consent to pursue a romantic relationship with Caleb. Shortly thereafter, following a celebratory dinner, a heavily-intoxicated Loomis tells Ann he loves her before passing out in his bed. Ann joins Caleb in the adjoining bathroom, where the two engage in sexual activity.

Further tensions arise between Caleb and Loomis following the sexual encounter. The two men finish the water-wheel, moving it and its wooden flume into place atop the waterfall. Encumbered by the bulky radiation suit, Caleb slips twice during his rope-assisted climb up the slick mossy cliff-side. During the second slip, the two men silently lock eyes, both holding the rope, while Caleb teeters on the cliff's edge.

Loomis returns to the farmhouse alone. Ann apologizes for her earlier indiscretion; Loomis tells her that Caleb decided to travel south, to the coast, in search of other settlements. Ann takes this news badly, chasing after Caleb but not finding him, and lapses into a sullen silence. The farmhouse's electric lights and refrigeration are restored. Ann finds that her beloved church organ and three roughly-fashioned pews have been moved into the barn. The two appear to exchange brief uncertain glances, Ann playing a hymn, Loomis sitting and clasping his hands, as the scene fades to black.