The special homicide case that was unsolved in 1997 resurfaced 13 years later. Criminal policeman Wei Zhengrong, who wasn't able to find out the real murderer that year was traumatised and left the front line. The once fledgling new policeman Lu Xingzhi grown from his innocence and has become a meticulous criminal investigation expert. The many coincidences of the case brought the master and apprentice together again to hunt down the real culprit.

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 young doctor is stunned to discover that her new mentor in the neurosurgery department is none other than her ex-husband! Can they find a second chance at love?