As often as possible high school senior Reiko Smith-Mori drives to the nearby California desert to escape from the increasingly claustrophobic life at home and her parents' expectations. There she meets Seth Rogers, a boy from school who shares her love of the desert but also wants a closer relationship with Reiko, which is just adding to her problems. Because Reiko has a secret: in her mind her older sister, Mika, who died years ago, is always with her, at home and school, and she has never allowed herself to say good-bye.