Taking up the new drama as homage to the 160,000 Chinese police officers combating crime on the front lines, Hui set aside other projects and committed one-and-a-half years to leading his team across the country for preparations. They meticulously observed the daily work and life of officers in various cities and scouted for the most suitable filming locations, ranging from Hegang in Northeast China's Heilongjiang province to Chongqing in Southwest China.
One of the moments he found most impressive was visiting Cui Daozhi, a 91-year-old expert revered as China's Sherlock Holmes. As a trailblazer among the country's first-generation forensic policemen, Cui participated in the on-site investigations of over 1,000 cases and identified more than 7,000 pieces of trace and physical evidence without a single error.
"Under rudimentary conditions at that time, Cui provided crucial evidence for many cases with exceptional dedication and professionalism," says Hui.
Scriptwriter Xu Meng interviewed over 200 police officers and gathered materials totaling 2 million words in eight months, creating 15 representative cases — all inspired by real-life stories.
Consisting of 38 episodes, the ensemble-cast drama intertwines the process of hunting and identifying criminals in these cases with the career trajectory of Qin Chuan, a committed police officer portrayed by Yu Hewei.