Brynn, a talented seamstress, is still residing in her childhood home, grappling with the profound grief of losing both her mother and her best friend, Maude. To find solace, she immerses herself in creating a detailed model town within her living room. However, an unsettling past incident seems to have turned the community against her, leading Brynn to live a life marked by anxiety, isolation, and loneliness.
One fateful night, she is jolted awake to find an intruder—who is, shockingly, a humanoid alien—inside her home. In her panic, she attempts to escape but is pursued by the entity. The alien employs telekinesis to immobilize her, but in a desperate struggle, Brynn stabs it in the head with a shard of her model town’s school bell tower, freeing herself from its grasp.
Upon venturing out, Brynn discovers that all electronics have ceased to function due to the alien's interference. She abandons her car along with the alien's body before heading towards the police station. En route, she witnesses the destruction of her neighbor's house and an overturned mail van, signs of the chaos in her once familiar town. At the police station, a shocking encounter awaits her as she meets Maude's parents, who are, coincidentally, the chief of police and his wife. Maude's mother, filled with disdain, spits in Brynn's face before leaving—a moment that deepens Brynn's isolation and distress.
Determined to escape, Brynn boards a bus, but her relief quickly turns to horror as several passengers, now possessed by other aliens, attempt to restrain her. She flees to a deserted church, where she visits Maude’s grave only to witness a disturbing sight: a group of people visibly influenced by small tentacled creatures underneath their skin.
That evening, back at her home, Brynn experiences another shock when a glowing light drags the alien's body out. She finds herself confronting two more creatures, leading to a fierce battle where she impales a smaller alien with a broken mop handle, a testament to her defiance and bravery.
However, her ordeal continues as she is captured by an alien-controlled man and dragged towards a flying saucer's tractor beam. In a last-ditch effort, she kicks him away, turning the tables momentarily. A much larger alien then hunts her down, and she cleverly entraps it in her station wagon, causing an explosion that destroys the creature, just as a flying saucer intervenes, extinguishing the flames.
Yet another humanoid alien soon telekinetically hurls Brynn through a wall, restraining her with a red ray. In a horrifying moment, it regurgitates a tentacled creature that invasively enters Brynn's mouth, plunging her into a vivid hallucination where her life appears unscathed and Maude is alive. Just as she begins to succumb to this false reality, Brynn fights back, tearing the creature from her mouth.
The alien then summons a flying saucer which creates a duplicate of Brynn to hunt her down. In a harrowing encounter, Brynn confronts her clone, kills it in a fierce battle, and escapes to a deserted road just as she is pulled into the alien's craft. Inside, Brynn is forced to relive memories of the tragic event that led to her ostracization; an argument with Maude turns deadly when Brynn inadvertently kills her with a stone.
In a twist of fate, the aliens release Brynn back to Earth, stripped of any controlling influence. Time passes, and Brynn finds herself living in her repaired home. In a haunting yet strangely comforting aftermath, she notices that every other resident of her town has fallen under the aliens’ control. Yet, contrary to her previous experiences, the townsfolk now welcome her with open arms, leaving Brynn to grapple with her newfound reality.
