A farmer and his wife awaken suddenly in the dead of night in their isolated cabin nestled deep within the woods. The husband arms himself with a gun, and together they venture outside to investigate the unsettling noises that have disrupted their slumber. To their horror, they discover one of their cattle horrifically mutilated, leading the farmer to exclaim, "...no bear could do that..." As they stand frozen in fear, their dog bolts into the darkness, only to whimper in terror as a low, menacing grunt echoes through the trees. The couple seeks refuge inside, trembling behind the door as they glimpse the shadow of a massive, hairy creature loom past their windows. After several tense moments, when they believe the danger has passed, they cautiously step back outside, where they find enormous footprints imprinted in the ground, evidence of the creature's presence.
Meanwhile, in the nearby town of Flatwoods, a man named Otis makes a stop at a gas station to grab some groceries. A devoted man-nurse, he cares for a crippled patient named Preston Rogers. As Otis is busy shopping, Preston peers through the car window at the dense wilderness that surrounds them, suddenly gripped with an inexplicable fear as he catches sight of a cliff. After Otis pays for his items, he and Preston embark on a thirty-minute journey to Preston's secluded cabin, where they will be far removed from civilization. Once they arrive, Otis helps Preston inside but realizes he's forgotten to purchase skim milk. Ignoring Preston's pleas to accompany him, Otis heads back into town, leaving Preston alone as the sun dips below the horizon.
As darkness envelops the woods, Preston starts hearing unsettling noises that prompt him to grab a pair of binoculars. He peers out the window and sees a Jeep pull up at the next cabin, where five women are unloading their belongings. Time passes, and Otis still hasn’t returned. One of the women leaves to make a phone call, and Preston watches her closely through his binoculars. However, when he briefly turns away to clean the lens, a gigantic, hairy creature bursts forth from the underbrush and abducts the girl. Confused and fearful, Preston looks back, only to find her gone. Moments later, the sound of a collapsing telephone pole indicates an ominous twist: with the line out, Preston's chance of calling for help vanishes.
As the sun sets further, Preston steps out onto the deck with a flashlight, finding a cell phone abandoned on the ground. It dawns on him that it belongs to the girl next door. Suddenly, he hears rustling in the woods and shines his light into a thick bush, only to be met with a pair of enormous, glowing red eyes glaring at him with fury. Terrified, he retreats into the safety of the cabin, panic setting in as he emails the local police force to report a “creature” lurking in the woods. When Otis finally returns home, Preston explains the horrifying events, but Otis dismisses his concerns and begins to prepare dinner.
Meanwhile, in a remote part of the forest, three men, including the gas station clerk and the farmer, embark on a camping trip to hunt down the very creature that has caused Preston distress. One of the hunters hears a noise and investigates, tracing a blood trail that leads him into a dark cave. Inside, he discovers the abducted girl, desperately pleading for help. Tragically, before he can get assistance, the monster arrives, dragging her into the shadows. The hunter races back to warn his companions, but one by one, they fall victim to the creature, incapacitated and taken deep into the woods.
Back at the cabin, Preston desperately reaches for the abandoned cell phone, sending a text message to the girls next door that reads, “Your friend was taken into the forest, GET POLICE!” As panic ensues, they realize their phone lines are inoperative, leaving them vulnerable and unsure of what to do. One girl, while in the bathroom, is suddenly yanked out through a tiny window by the monster, leaving the others in utter shock. Witnessing these horrors unfold, Preston implores Otis that they must flee, but Otis attempts to sedate him with a syringe. In a desperate moment, Preston manages to turn the tables and sedates Otis instead, knocking him unconscious.
In a terrifying twist, as Preston regains his composure, the monster's face presses against the cabin window, roaring in a display of raw power. Preston faints from sheer terror. Simultaneously, the police receive his email but are skeptical, suggesting Preston might just be playing a prank. When the girls return to check on their friend, they discover the blood-splattered bathroom and the broken window, heightening their fear. Preston raises his voice, trying to warn them of the lurking danger outside. Just as he shouts for them to steer clear of the windows, the monster breaks into the cabin, mercilessly slaughtering everyone inside, leaving only one girl as the unlikely survivor who manages to escape to Preston's cabin.
Desperate to calm the terrified girl, Preston begins recounting his tragic backstory—how he and his wife had suffered a devastating rock climbing accident just six months prior, which left him paralyzed and killed his wife. Together, they devise a plan to email the police again; however, the power suddenly slips away, plunging them into darkness. With a sense of urgency, they arm themselves with an axe for self-defense and prepare to escape using a harness to safely descend from the deck to the ground below. As they make their way down, the monster bursts into the cabin, grabbing the girl and hoisting her high.
In a heartbeat, Otis awakens and joins the battle, stabbing the monster in the back with the axe, prompting it to release the girl. She manages to climb down swiftly, but as Preston and Amanda make a frantic run for Otis's car, the monster relentlessly pursues them. With the vehicle barely within reach, Amanda finally starts the engine. Just then, the beast targets them, lifting the car off the ground, only to drop it moments later, allowing them to speed away in terror. However, a few hundred yards down the road, Amanda crashes into a tree, and as she flies through the windshield, she is knocked unconscious, leaving Preston in the car, facing the approaching monster.
In a last-ditch effort, Preston toots the horn, startling the monster just enough to make it drop Amanda. Realizing the horn poses no real threat, the creature surges forward. In a fierce struggle for survival, Preston puts the car in reverse and slams on the gas, sending the vehicle crashing into the monster, pinning it against a tree, impaling it with the axe still lodged in its back. As the creature writhes in pain, Preston finds a way to crawl towards Amanda while ensuring the car doesn't move, ultimately leading to the monster passing out.
Having survived this harrowing ordeal, they eventually find themselves on the roadside, where the police arrive to whisk them away to safety. At the hospital, both Preston and Amanda recount the gruesome events to the officers, detailing the massacre at the cabin. Filled with dread, the police rush to investigate but are met with a chilling discovery: the bodies they expect to find are nowhere in sight. Instead, they encounter Otis's car backed into a tree, and the presence of the monster becomes undeniable. The climactic film concludes with the terrifying revelation that not just one, but dozens of monsters are lurking in wait, leaving the audience with an eerie sense of suspense and disbelief.
