On 1949 October 1, the day of the founding ceremony of the People's Republic of China, Xiao Dali enters the city and is reorganized as the director of the public security police station. He finds that primary school teacher Feng Jingbo is full of doubts. With the high vigilance of a soldier and the sense of responsibility of a public security official, Dali insists on partnering with Feng and becomes his neighbor. He then spends his whole life carrying out a nearly four-decade pursuit without regrets.

A song brings together a daughter and her estranged mother, telling their individual stories spanning two generations across three cities.

Xia Mu is a troubled child whose salvation comes in the form of Shu Yawang. When something terrible happens to her, he seeks revenge. Nothing is the same in their lives after that.