Tianguang (played by Guo Jinan) is the CID of the serious crime team. He is upright and has a clear distinction between right and wrong. When investigating a serial murder case, he found that the suspect was actually a prisoner who escaped from his father 20 years ago. Tianguang's father Dahe (played by Hui Shaoxiong) is a mediocre policeman, who is careless and unmotivated. Not only did he let the criminal escape, but he also died in the bed of a prostitute, which made Tianguang and his mother suffer great humiliation. Gao Shan (played by Chen Huishan), a writer famous for writing live novels, also tracked the case in Tianguang's hands this time. The different understandings of the case between the two caused friction, and they competed for the truth. One day, Tianguang found that his father's old phone rang magically. The other party claimed that he was a policeman, but what he said was stuck in the 1980s. After asking carefully, he found that it was his father Dahe 20 years ago! The two cooperated seamlessly, spanning two time and space, and jointly tracked down the real murderer.