Ice City, 1937

During the fall of Ice City, a street thug accidentally saves Qian Jinghui, chief of the police station, and becomes his informant. While helping Qian solve cases, he punishes evil and upholds justice, frames traitors collaborating with the Japanese, and grows entangled with a beautiful police inspector and the station chief’s secretary. Caught between various factions, he turns his life around and becomes a police officer, rising step by step to head the station’s Criminal Investigation Division. As he works cases, he gradually comes into contact with agents from all sides and provides them with a wealth of intelligence. After observing them all, and under the influence of his childhood friend Wen Wanqiu, he ultimately sets foot on the right path…