After spending her life with her mentally retarded mother and agoraphobic neighbor, twelve-year-old Heidi sets out from Reno, Nevada, to New York to find out who she is. Living with her mentally disabled mother who only knows just over twenty words, young Heidi has learned to live in her special world until a new word is suddenly used and repeated by her mother; causing Heidi to think it might be a key to a secret past about which she knows so little.