Blind and deaf after suffering a terrible fever as a baby, young Helen Keller (Patty Duke) has spent years unable to communicate, leaving her frustrated and occasionally violent. As a last chance before she is institutionalized, her parents (Inga Swenson, Andrew Prine) contact a school for the blind, which sends half-blind Annie Sullivan (Anne Bancroft) to teach Helen. Helen is initially resistant, but Annie gradually forms a bond with her and shows Helen ways of reaching others.