Lin Feng, a legal police officer in 2025, accidentally took DeepSeek's fragmented memory with him and traveled to 1949, becoming an 18-year-old police recruit with the same name. Losing his sense of modern superiority, he started by taking over the old police station in Peiping, and learned how to hold a gun and the law amidst the smoke of Sute's uprising against hegemony. During seventy years of ups and downs, he personally experienced the wave of land reform, the suffering of famine, and the whirlpool of the Cultural Revolution. He also personally promoted the reconstruction of the rule of law after correcting chaos. From bicycle patrols to directing modern criminal investigations, from the era of food stamps to the tide of market economy, Lin Feng measured every pulse of the Republic with the eyes of a policeman. This is not a cool article that predicts the future, but an epic story in which a time traveler uses his blood and loyalty to protect the peace of a place in the torrent of the times and grows together with the public security cause of New China. When the military parade salute sounded, he looked back where he came from and had no regrets about the weight this police uniform carried.