One day, Mac hears noise outside his cabin, and rushes out to find an old woman and a younger woman standing outside his door. The old woman introduces herself as Kathryn, and the younger woman as her daughter, Milja. Kathryn offers Mac some jewelry and seeds in exchange for some of his crops, but he declines, all the while holding them at gunpoint. Finally, Kathryn offers him Milja, and an agreement is made for sex with the young woman in exchange for food. Mac locks Kathryn in a back room while he and Milja have sex.
The following morning, Mac tells the women to take their belongings and leave. Kathryn steps outside and Milja is about to join her, when suddenly she returns inside and takes a razor and some soap. Milja caresses his face, before softly shaving him.
Kathryn and Milja have been allowed to stay. Over the following days, they fall into an uneasy domestic routine alongside Mac; they farm during the day, eat dinner together in the evening, and then Milja and Mac have sex every night. However, Kathryn and Milja plan to secretly kill Mac in order to reduce the amount of supplies being used. One night, on Kathryn's orders, Milja steals the two last shells from Mac's shotgun. The next morning, before their plan can be put into action, Milja is abducted by a drifter while bathing in the stream. After Mac is alerted by an out-of-place footprint in the mud outside the cabin, he takes off into the woods after Milja and her assailant. After tracking them down, Mac tries to load his shotgun but realises that his shells are missing. As a result, the assailant is able to shoot Mac in the stomach. The assailant approaches the wounded man, intending to shoot him again in order to kill him, but Mac pulls out his knife at the last second and slits the assailant's throat. Back at the cabin, Milja and Kathryn treat the Mac's wound, prying the bullet out and cauterising the wound. When the wound becomes infected, Kathryn wants to let him die, but Milja convinces Kathryn to help nurse him back to health.
One night, after Mac has returned to full health, a band of raiders arrive at the cabin. Mac gathers Milja and Kathryn, and informs them that he counted six raiders. Armed with only a shotgun with two shells and a pistol with one bullet salvaged from Milja's abductor, they decide that they are outnumbered and cannot fight back. They have no choice but to keep quiet while the raiders attempt, but fail, to break into the cabin. The following morning, Mac, Kathryn and Milja emerge from the cabin to discover that their farm has been ransacked and all of their crops have been stolen. In the following days, they work to save the farm, but they begin to slowly starve. Meanwhile, Milja discovers she is pregnant and attempts to perform an abortion on herself with a length of wire, but she fails. Kathryn again floats the idea of killing Mac, explaining that there is only enough food for two people. Milja agrees that there is only enough food for two people, and suggests poisoning Mac. That night, Milja makes a meal with poison mushrooms.
The following morning, Kathryn tells Mac that she and Milja are leaving. Milja tells her she wants to stay; Kathryn immediately goes to the sink and vomits, realising that Milja has poisoned her instead of poisoning Mac. Resigned to her death, Kathryn tells Mac to cut her wrists and bury her after she dies, which he does. On the way back from burying Kathryn, Mac finds two rabbits caught in some of his traps, which would have been enough food for three people had Kathryn survived. Mac returns to the cabin, and tells Milja about his brother while preparing the rabbits to eat. He tells her that they used to steal supplies from camps, until one night when they were caught and chased. Realising that there was no way that both of them would escape alive, Mac cut his brother's Achilles tendon and left him to die. Mac tells her that he did what he had to do to survive; in telling her this, he reassures her that she did the right thing in poisoning Kathryn. Shortly thereafter, Milja wordlessly informs Mac that she is pregnant by placing his hand on her belly.
Mac and Milja are out foraging one day when they notice that the raiders have returned. Mac decides that they need to leave the farm, but before they can, they need to collect their storage of crop seeds. Milja sneaks into their green house for the seeds and Mac stands watch while the raiders ransack the cabin. Milja successfully grabs the seeds; on her way out, she grabs a machete, which makes a noise and alerts the raiders to her presence. Milja and Mac run into the woods, but the raiders give chase. After the raiders surround them, Mac sees a vision of his brother. He tells Milja that his brother's name was Augustus, before instructing her to run while he distracts the raiders. Mac begins playing the harmonica, drawing the raiders towards him and away from Milja. One of the raiders stumbles onto Milja's location, but she lures him into a bear trap and makes her escape. Mac manages to shoot and kill one of the raiders, but he is eventually shot with a crossbow bolt. His dying body is looted next to a large spit and fire made from the cabin's wood, implying that the raiders are cannibalistic.
Milja wanders the woods alone for a long time, until she eventually arrives at a large compound, surrounded by barbed-wire fences and patrolled by armed guards. She walks up to the gate and hands her bag and her machete over to the guard on the other side. The guard runs off into the compound. Confused, Milja turns to a female guard and asks her what happens next. The guard tells Milja that a vote will be held to decide whether or not to let Milja stay. The guard then realises that Milja is pregnant and asks if she knows what she will call the baby. Milja answers, "If it's a boy…"
Mac lives another day, and escapes from the cannibals, clinging to life. Will he be able to recover?