In a dystopian future, two teenage sisters, Nell and Eva, find themselves isolated in a remote home alongside their father, amidst a catastrophic continent-wide power outage that signals a complete technological breakdown. With their car battery dead, they are left stranded for a prolonged period. Eventually, their father manages to restore the car, and they venture to the nearby town, where they purchase essential supplies, including gas from a man named Stan. While Eva attends her dance class, Nell spends time with her boyfriend, Eli.
Upon returning home, they come across a stranded vehicle. Their father's attempt to assist the occupants is met with hostility as they brandish weapons. He then declares that they will not return to town until power is restored. Tragedy strikes when he injures himself severely while cutting down a tree — a chainsaw accident that leads to excessive bleeding. In his final moments, he urges the girls to look after one another and express their love. They give him a proper burial in the very forest where he perished.
After two months living without electricity, the sisters' food supplies dwindle. They rely on the survival skills their father imparted, though they deeply miss the comforts of their previous life. Eva, for instance, is forced to dance to a metronome in the absence of music.
One fateful night, Eli appears, having trekked to find Nell, sharing disturbing news about the surrounding houses being abandoned. In a pivotal moment, Nell shares her first intimate experience with Eli, who later persuades her with tales of a restored Boston where life has resumed — promising electricity, food, stability, and job opportunities. Despite his allure, Nell's sense of obligation to her sister pulls her back home after just one night away. Demonstrating resourcefulness, she researches edible and medicinal plants while foraging for food. Their bond deepens with a moment of celebration when she confirms she is not pregnant.
As six long months pass in darkness, a harrowing turn of events unfolds when Stan assaults and rapes Eva, stealing the majority of their remaining gas and vehicle. This propels Nell to reinforce their home, readying herself with a gun for safety, while Eva becomes increasingly confined indoors. At eight months into their ordeal, Eva discovers she is pregnant. While Nell suggests an abortion, Eva expresses her desire to keep the baby, arguing that no child should be born unwanted and emphasizing the individuality of the unborn. To support Eva through her pregnancy, Nell takes on the responsibility of hunting and butchering pigs for sustenance.
Fifteen months into their survival, a storm wreaks havoc on their already fragile home, causing it to deteriorate further. As Eva goes into labor, the sisters seek refuge in a hollowed tree stump that once served as their childhood retreat. Amidst the chaos, Eva gives birth to a healthy baby boy, bringing a semblance of joy in their harsh reality. Later, determining that their safety is compromised, Eva decides to set their house ablaze using their remaining gas. They carefully gather cherished items — books, keepsakes, and a family photo — and, as night falls, they ignite their former home before embarking on a new journey into the depths of the forest, leaving behind the ashes of their past.
