Synopsis：Nine-year-old Wu Nan carries the sins of his past life and is determined to atone in this life through extraordinary deduction. He solves a bizarre murder case in the neighborhood ahead of everyone else, peeling back layer after layer to reveal the hidden case within a case, shocking the entire police department.Facing the difficult 1213 cold case, Wu Nan withstands pressure from all sides and, with a calmness and intelligence far beyond his age, directs the major crimes unit in a full investigation, cracking the case within just a few days. Although he is maliciously reported during the process, he wins over everyone with irrefutable, brilliant reasoning, ultimately earning the resounding title of “the Nine-Year-Old Detective.”