A formal notice sets the premise: Thomas Finley has been convicted of raping and killing his sister, and murdering Edgar Lauren, a psychic. He claims a demon carried out the murders, though the court treats him as the killer. He is sent to prison, where he ultimately takes his own life.
Back at home, Thomas’s younger sister Samantha Finley and their mother Ellen believe Ellen has been able to contact her deceased husband, David. Soon after, the family starts insisting that a malevolent presence is haunting the house. At first they assume it might be David’s spirit, but after a string of terrifying attacks on Samantha, they grow certain that a darker force is at work.
One night the camera captures Ellen sitting up in bed and leaving her bedroom, wandering into the living room. She writes something on a scrap of paper, crumples it, and returns to her room. Thomas finds the note under Samantha's pillow and reads the word: MARON. He worries that a supernatural threat has arrived and suggests Ellen and Samantha stay at a hotel while he booby-traps the house with bells and wire. When the bells ring, the rigged perimeter is violently compromised: the wire and bells tear away from the wall and are hurled at him. He bolts into the bedroom, and the demon pounds on the door in a display of raw aggression.
Ellen calls in a panic, claiming the demon followed them and attacked Samantha. Back at the house, Samantha experiences a brutal episode, bending over in pain as the influence intensifies. Later that night Thomas wakes to find Samantha missing; he spots the attic ladder lowered and climbs up to find his sister standing there in her underwear, seemingly immersed in a trance. Upon waking, she cannot remember what happened.
Desperate for answers, Thomas asks the house’s previous owner whether anyone named Maron ever lived there, but the owner doesn’t recognize the name. A scream from Samantha shatters the moment; Thomas rushes to the bathroom and discovers her lying topless in the bathtub, deeply traumatized. Ellen awakens to thuds and, in the living room archway, stands with a knife before retreating to her bedroom. Later, Thomas awakens to a slammed door and learns that Ellen has slit her wrists; she is taken to the hospital.
Dr. Edgar Lauren arrives to help, explaining that a powerful dark entity inhabits the home and has fixed its attention on Samantha. He clarifies that MARON comes from Old Germanic roots and means “nightmare,” a creature akin to an incubus that assaults women in their sleep. The psychic vows to help expel the entity, and the scene cuts to black as he prepares to confront the malign force.
After a pause, the story returns through a disturbing camera POV. The doctor’s bleeding head and lifeless face appear, lying on the floor and angling toward the lens as Thomas screams. He grabs the camera and hurries to Samantha’s room; the house lies in disarray. He finds his sister naked and levitating in her room, her body smeared with blood, seemingly being raped by an invisible demon. He drops the camera, and an off-screen, gurgling noise is heard as an unseen figure picks up the device and tilts it toward Samantha’s lifeless face.
Thomas is subsequently charged with Samantha’s rape and death and is sentenced to life in prison. Not long after, he takes his own life. In the wake of the tragedy, Ellen also commits suicide. A year later, the very recording Thomas made is discovered in the family attic, a chilling reminder of the horrors that unfolded within the walls of their home. The story lingers as a stark and unsettling account of a family ensnared by fear, grief, and a malevolent force they could not escape.
