Francisca and her parents are settled on a farm where they raise various animals. Her mother, a skilled surgeon, imparts her knowledge to Francisca, teaching her how to remove the eyeballs from the livestock, while also sharing the tale of St. Francis of Assisi. One fateful day, a door-to-door salesman named Charlie arrives, requesting to use the restroom. Despite her instincts telling her otherwise, Francisca's mother permits him entry into their home. Unfortunately, Charlie reveals his sinister intentions by brandishing a gun and dragging Francisca's mother to the bathroom. When her father returns home, he is horrified to find Charlie brutally attacking his wife's body in the tub. In a fit of rage, he knocks Charlie unconscious and confines him in the barn, while the family mourns the tragic loss of Francisca's mother by burying her in the backyard.
As time passes, Francisca visits the captured Charlie, who intrigues her with tales of the thrill associated with taking lives. In a shocking act, she removes Charlie's eyes and vocal cords, preserving them in a bag within the refrigerator. She reassuringly tells him that he was spared because he is her only friend, and she vows to protect him.
Years later, after the death of her father, Francisca chooses to preserve his body as well. She later meets a young woman named Kimiko at a bar. As they connect, Kimiko becomes uneasy upon learning about Francisca's dark past, especially when Francisca makes a chilling joke about having killed her own father. Attempting to flee, Kimiko meets a tragic fate as Francisca murders her, dismembers her, and stores her organs away in the refrigerator. Following this, she bathes Charlie, who remains shackled in the barn, and brings him into her bed. However, when Charlie tries to escape, Francisca stabs him repeatedly. With eerie confidence, she acknowledges that he was right—killing is an exhilarating experience.
Yet, consumed by solitary despair, Francisca wanders through the woods until she stumbles upon a highway, where she gets a ride with a woman named Lucy, who has a baby son named Antonio. Upon reaching her home, Francisca seizes the opportunity to kidnap the baby, brutally stabbing Lucy and praising her deceased mother for guiding them together. True to her twisted nature, she removes Lucy's eyes and vocal cords, chaining her up in the barn as well.
As Antonio grows and approaches 8 or 9 years old, his curiosity piques about the barn, which he is explicitly told to avoid. One night, upon seeing Francisca asleep, he bravely ventures inside, only to be horrified at the pitiful sight of his biological mother, chained and blind, moaning in despair. Lucy eventually manages to escape the barn, wandering blindly until a truck driver finds her on the road. However, Francisca soon learns of this escape, prompting her to unearth her mother’s remains, cradling the skeleton while lamenting her loss.
In a climactic turn, as police arrive at the house, Francisca rushes to awaken Antonio, dragging him into the bathroom while brandishing a knife. In a frantic plea, she insists that the authorities will never take her baby away. Just then, a gunshot echoes in the air, leaving the film's tragic conclusion shrouded in mystery.
