On the morning of November 22, 1963, April Winford, fifteen, takes the school bus from where she lives on a lake in the Texas Hill Country to the small town of Llano, twenty miles away. Her thoughts are concentrated on Moona, the filly she has acquired as a kind of reward for having had to move already six times due to her father's profession of building factories. She is acutely aware that she is an oddity in Llano, and although she does her best to blend in with her classmates, she finds she has most in common with Ronnie, a girl who is shunned because of her dark skin. They are both ardent admirers President John F. Kennedy. When the shocking news of Kennedy's assassination is announced over the PA system and a classmates cracks a joke, it is the kickoff of increasingly dramatic events for both April and Ronnie. It is a time of facing life's hard realities but also learning to love and forgive.

Violet, April's mother, has born six children is six different states. She has always soldiered on, setting up households wherever her husband, Ray, took the family, but when he takes another job abroad, she stays behind at the lake where Ray has set his three eldest up in a construction company. Haunted by traumatic events from her early life, questioning Ray's devotion, resentful at her grown children who appear to have cast her off, and incapable of comprehending her headstrong daughter, she veers ever more off her rails. She takes to hanging out in dark bars and drinking with men she has met at the lake.

A rare bird nests exclusively in the Texas Hill Country, and Clay, a young biologist, is determined to save it from extinction. He gets help from April, who finds herself increasingly drawn to him, even though she has long determined that she will never end up like the other adult women around her.