In 1964, eleven-year-old Harriet M. Welsch is an aspiring writer who lives in New York City's Upper East Side. Harriet is precocious, ambitious and enthusiastic about her future career. Encouraged by her nanny, Catherine "Ole Golly," Harriet carefully observes others and writes her thoughts down in a notebook as practice for her future career, to which she dedicates her life. She follows an afternoon "spy route", during which she observes her classmates, friends, and people who reside in her neighborhood. One subject that Harriet observes is a local store, where the younger son Fabio cannot make anything of his career in contrast to the hardworking and loyal Bruno, and where the stock boy Joe Curry or "Little Joe" is eating in the storeroom and feeding homeless kids instead of working.