Hulan: the Unsolved Mystery

In the small town of Hulan on the northeastern border, a series of bizarre murders broke the tranquility of winter. Mysterious ancient symbols are left on the bodies of the dead, and all clues point to a forgotten legend - the "Unsolved Mystery" at the bottom of the Hulan River. Young detective Lin Mo was ordered to investigate, but found that three generations of his family were inextricably linked to this unsolved case. As the investigation deepens, he gradually uncovers the shocking secrets hidden behind the century-old city of Hulan: unsolved cases from the Republic of China period, missing files from special periods, and a revenge plan that spans half a century. When the truth gradually emerged, Lin Mo discovered that he had been deeply involved in it, and the real "unsolved mystery" may be hidden deep in his own memory...