Shy Sarah Nelson and her father have spent the past decade moving from one Texas town to another. She barely remembers her mother, who has lived in a mental institution since Sarah was two. Now Sarah is about to turn twelve, and she has lots of questions. What is her mother like? How will Sarah know how to be 'a real woman' without a mom to look up to? And why is her best friend, Lisa, so obsessed with getting a kiss some French guy invented?

For help, the word-loving Sarah starts writing letters to her hero: To Kill a Mockingbird's Atticus Finch. And as the summer passes by, she gets to know her cul-de-sac the way Atticus knew Maycomb: she grows close to the grandmotherly Mrs. Dupree, watches her cool college-aged neighbour fall in love, and discovers the boy she wants more than anything to be her first kiss.

For once, Sarah begins to feel like she belongs. But when the news trumpets the reason Sarah's mother is in an institution - for drowning Sarah's twin brother in the kitchen sink - Sarah feels like she might not have figured out as much as she hoped. In the end, however, Sarah finds the bravery to tell her crush how she feels, to stand up to her father, and to finally go visit her mother - and she knows she'll never forget this summer.