Deputy Chief Cui Daqing of the Fengtai Town Police Station in Beijing's Fengtai District begins his busy day. Leading officers Huang and Su Ming, among others, he sets out to apprehend a bicycle theft gang. Just then, Cui's wife calls, saying their son Didi had fallen seriously ill. With no time for family matters, Cui orders the driver to proceed. But resident Mr. Zhao, caught up in his own personal dispute, refuses to let the car pass.

Xiao Dou is a shy and naive mailworker living in Beijing with his sister. When a coworker is fired for reading people's correspondences Xiao Dou takes over the same mail route. He soon finds himself indulging in the same curiosity, eventually developing an obsession. Xiao Dou chooses to spend time reading letters instead of socializing with friends or coworkers. As he becomes increasingly tied to the letters, he begins to intervene in the lives of those who write and receive the letters.