Helen Keller, a young girl left blind and deaf after an illness in infancy, lives in near-isolation, unable to communicate with those around her. Her parents, Captain Keller and Kate Keller, are at their wits' end, struggling with Helen’s violent outbursts and a lack of education. Desperate for help, they reach out to the Perkins Institute for the Blind, which sends them a young, determined teacher named Annie Sullivan. Annie, partially blind herself, arrives at the Keller home to begin the seemingly impossible task of teaching Helen how to communicate.

Annie quickly realizes that Helen has been given no boundaries or discipline, making her task even more daunting. Through persistence, creativity, and sheer force of will, Annie begins a rigorous process of teaching Helen sign language by spelling words into her hand. Despite facing resistance from both Helen and her family, who are skeptical of her strict methods, Annie’s unwavering belief in Helen’s potential drives her to push forward. Their relationship evolves from one of initial hostility to a profound breakthrough, marking the beginning of Helen’s journey to understanding and communication.