Mary Ann Robinson, a young woman living in The Bronx, New York, with her neurotic, overbearing mother and kindly but ineffectual stepfather, is raped while walking home one night. Keeping the attack to herself, Mary Ann runs away, seeking to lose herself in Manhattan by renting a seedy flat and taking a job in a dime store. Overwhelmed by people's hostility and her own despair, Mary Ann tries to jump off the Manhattan Bridge, only to be stopped by Mike, a garage mechanic who takes her back to his modest basement apartment nearby. At first appreciative of Mike's kindness, Mary Ann becomes terrified when he refuses to let her leave. Is Mike really Mary Ann's rescuer - or is he another rapist?