Pauline, a disturbed and antisocial high school student with a deeply rooted obsession with surgery and bodily functions, lives under the oppressive rule of her controlling mother, Phyllis, while her meek father, Bob, offers little support. Pauline's younger sister, Grace, suffers from cystic fibrosis, and their gender-conforming household only adds to Pauline's mounting frustrations. She often retreats into violent and vivid fantasies involving blood and medical procedures, which she perceives as a way to gain control over her surroundings and assert her complex desires and perversions. Her morbid interests cause severe social isolation and label her as an outcast among her peers, further driving her to rebellious and often shocking behavior as she seeks validation and a twisted sense of purpose.

As her fascination with surgery intensifies, Pauline's mental state deteriorates, marked by increasingly disturbing hallucinations and dreams. Her strained relationship with her family exacerbates the tension, particularly with her mother, who is intent on maintaining appearances and normalcy. Pauline's fixation on performing a groundbreaking surgical procedure on Grace reaches a fever pitch, leading her down a dangerous path. She refines her knowledge and skills through increasingly extreme methods, building towards a climactic and unsettling endeavor. The escalating conflict within her home, alongside her unraveling sanity, creates a harrowing narrative that explores the depths of her psyche and the dark consequences of obsession.