As an infant, Helen Keller (Patty Duke) has scarlet fever and becomes blind and deaf. Her wealthy parents cope as best they can, but they end up spoiling Helen so terribly that she turns into a monster who is pretty much allowed to do anything she wants to do. As she grows up, and the parents are no longer able to deal with her temper tantrums and erratic behavior, they employ Annie Sullivan (Anne Bancroft) as her teacher. Annie has limited sight herself, so she can identify with Helen. Annie realizes that Helen needs strict discipline. However, Helen’s parents perceive Annie as being too harsh with Helen and continue to intervene during Annie’s attempts to discipline the child. Discouraged Annie decides to leave the household. However, she doesn’t really want to, so she comes up with a plan whereby if the parents agree to let her spend time alone with Helen in a little cottage on their property without intervening, she’ll try again. At first it’s a battle of wills between Helen and Annie, and Helen’s mother has a hard time staying away, but Annie eventually is able to reach the isolated child.