Twelve-year-old Ma Tianshan, raised in a desert frontier army farm, returns one scorching summer to confront a buried family secret: Is his ruthless foster-father Ma Hongguang truly his parent? The return of Shanghai youth Kong Xiaoxue, rumored to have borne a child with the outcast herdsman Li Dalin, upends Tianshan’s world.

A geological team travels to the hinterland of Lop Nur to conduct potash surveys.