Sixteen-year-old Olive Alexander has lived on a ranch in the Jornada del Muerto region of southern New Mexico her entire life. But when World War II begins, the government seizes her family's land for the construction of a new, top secret Army post. While her mother remains behind, Olive is forced to live in nearby Alamogordo with her grandmother and find a place in a new school. When Jo Hawthorne crosses her path, Olive sees a chance for friendship--until she learns that Jo's father is the Army sergeant who now occupies her beloved ranch. Already angry about her new reality, Olive pushes Jo away. But as she struggles to make sense of her grandmother's lapses into the past and increasingly unsettling hints about what's happening at the ranch, she slowly warms to Jo's winsome faith and steady attempts at friendship . . . until one devastating day when the sky explodes around them and their lives are torn apart. Seven years later, Jo returns to Alamogordo, still angry and wounded by the betrayals of that fateful day. Determined to put the past behind her once and for all, Jo hunts for answers and begins to realize the truth may be far more complicated than she believed, leading her on a desperate search to find her friend before it's too late.