Following the accidental death of her deaf father, Dot, an orphaned teenager who is also
deaf-mute, is sent to live in
Meriden, Connecticut, with her upper-class
godparents, Paul and Olivia Deer, and their teenage daughter, Nina. Dot and Nina had been friends in childhood, before Dot lost her hearing as a result of a medical condition. The aloof Nina resents Dot's presence in the home and insults her repeatedly. Meanwhile, Dot observes that Olivia, an unfulfilled
interior designer who was close friends with Dot's mother, is an alcoholic with a prescription drug addiction. Late one night, while returning to her bedroom, Dot observes Paul raping Nina in her bedroom, unbeknownst to them. It becomes clear that Paul has been sexually abusing his daughter for years. At school, Dot is a social outcast, though Connor, a basketball player, takes an interest in her, much to the chagrin of Nina's abrasive friend, Michelle, who is pursuing him. One afternoon, Nina returns home early from cheerleading practice and overhears Dot playing
Beethoven on the family's piano. When one of the strings breaks, Nina hears Dot swear loudly, before vocally
harmonizing with the strings as she tunes them. Realizing Dot is neither deaf nor mute, Nina withholds her knowledge of this. At lunch the next day, acting under the guise that Dot cannot hear, Nina assays her by confessing her hatred of her father, and details her plan to murder him. That evening, Dot goes on a date with Connor, who is able to communicate with her by
lip reading. Dot returns home to find Paul and Nina in bed together, and deliberately breaks a vase in the hallway, interrupting; Nina realizes the action signifies Dot's alliance with her. Later, Dot comforts Nina in her bedroom as she cries herself to sleep. The following night, after a basketball game, Connor confides numerous personal secrets to Dot, including his
attention deficit disorder and his chronic masturbation. The two proceed to have sex in the school swimming pool. Meanwhile, Nina returns home from the game and is visited by Paul in her bedroom while she irons her cheerleading uniform. Mustering the courage to proceed with the murder, Nina tells him to close his eyes, and that she has a secret to show him; she proceeds to approach him with the hot iron to burn his face, but is interrupted when Dot returns home. Nina puts the iron down, and instead lies to her father that she is pregnant with his child and needs a thousand dollars for an abortion. He agrees to give Nina the money the next day. Nina and Dot prepare to attend the school's spring dance the following night. While getting ready, Nina tells Dot she is going to kill Paul that night and run away with the abortion money he is giving her. She explains that she will find work as a stripper, believing she can become famous "like
Courtney Love." Before the girls depart for the dance, Paul confronts Nina after finding
tampons in her purse, and accuses her of lying about the pregnancy. Meanwhile, Dot, who is playing "
Moonlight Sonata" downstairs, hears the argument. The confrontation becomes violent, and eventually descends into a rape before Dot comes to Nina's defense, strangling Paul to death with a piano wire. Olivia, in a drug-induced stupor, stumbles upon the scene, unfazed by her husband's corpse, but amazed by the revelation that Dot can hear. Michelle arrives at the house to pick Nina and Dot up. The two quickly change their dresses, which are soaked in blood, and leave. At the dance, Dot reveals to Connor that she can hear and speak; angered by her deception, he storms away. Nina and Dot leave the dance, and walk to a riverbank in the woods, where they bury a backpack containing their blood-soaked clothing. Nina asks Dot why she pretended to be deaf-mute. Dot explains that, after her mother died during her childhood, she stopped speaking and began communicating only with
sign language, as it made her feel closer to her father. When the girls return home, they find police cars at the house, and Olivia turning herself in for Paul's murder. Olivia apologizes to her daughter, and atones for having allowed Paul's sexual abuse of Nina go ignored. The following morning, Nina and Dot sit together and play piano, freed from their respective fathers. ==Cast==