On the outskirts of a small town, Elizabeth returns home to find her house broken into and her younger brother, Little Bob, abducted. She chases the kidnappers into the woods with a rifle, but steps on broken glass and hurts her foot, losing sight of them as they slip away. The town declares the pair missing and imposes a curfew for its youth, casting a shadow over the community.
Meanwhile, a troubled teenager named Killian is frequently bullied, though his older brother, Crawford, stands up for him. They live with their Aunt Marsha after their abusive veteran father died and their mother’s health declined, a harsh backdrop to the drama unfolding in their lives. One weekend, with Marsha away, Crawford persuades [Killian] to join him and his friends in the woods for a late-night gathering.
The brothers find themselves in a different part of the woods from Crawford’s friends, drawn to an old treehouse high in a tree. Inside, they discover a shaken Elizabeth, who explains there are creatures in the woods and that she escaped by climbing into the treehouse. She insists those creatures are still searching for her, and Crawf ord agrees to fetch help while [Killian] stays to protect her.
After Crawford leaves, [Killian] reaches out to Crawford’s girlfriend and her friends via a walkie-talkie. Through the static, they reveal they’re waiting and believe Crawford stood them up. Killian urges them to flee, but they don’t take him seriously, and they are attacked by unseen creatures. Arielle escapes, but her friends are killed, and she is eventually found and killed by one of the creatures after telling Killian that Crawford’s bike wasn’t there when they arrived.
With Elizabeth and Killian isolated, they reason that Crawford must have made it to the bike and escaped. Supplies run low and Elizabeth bleeds from her foot, yet they push on, hoping to find a way out. The creatures taunt them by hanging the bodies of Crawford’s friends from trees, calling Killian’s name in hoarse whispers as he investigates their surroundings. A distant smoke trail offers a glimmer of hope, and they decide to move toward it.
At dawn, they discover an empty house near the source of the smoke. Elizabeth replenishes herself, and they search for a way to contact help. Inside, Elizabeth finds a rotting corpse in a bedroom, and Killian discovers a burned body on a cross, which he identifies as Crawford. The tension intensifies when three men arrive at the house, with Crawford’s bike in their possession, and Killian slips into hiding while Elizabeth hides after discovering photos of the men posing with her little brother’s body. The men are implied to be the psychotic sons of the dead woman, living as monsters for their own dark amusement.
The intruders quickly close in on Killian, and Elizabeth intervenes just in time, but she is knocked unconscious as the men pursue Killian. In a fierce struggle, Killian defeats the medium-sized brother, then confronts the large brother as he attacks. Although Killian hurls a knife into the large brother’s chest, the man survives, forcing Killian to flee and reunite with Elizabeth, who is again on the run with him. They are pursued by the smallest brother, and a chaotic chase ends with tragedy on the road: they cause a police truck to crash, killing the officer, and then use the officer’s pistol to kill the small brother, leaving only the large brother standing.
The pair grieve the deaths of their siblings, sharing a quiet, aching moment before a new, dangerous determination takes hold. They discover a pair of assault rifles in the trunk of the police truck and resolve to track down the large brother for revenge, regardless of the legal consequences they might face. The final image lingers on their resolve as they each take a rifle and head back into the woods, ready to confront the danger that took so much from them and to claim justice in their own hands.
