London, the early 1950s. Born deaf, Mandy is mute for most of her childhood. As she reaches school age her family itself is in danger of breaking up. Christine , Mandy's mother has heard of a residential school for the oral education of the deaf, where the children are taught to lip-read and, through the identification of objects, to speak, but her husband Harry wishes to have her home-schooled. Their disagreement over the child's education results in bitter quarrels until Christine decides to leave him, taking Mandy with her. Mandy finally enters the school, run by a dynamic and gifted teacher, Searle.