The Second Major Crimes Unit of the Binhai City Criminal Investigation Division consists of five officers with very different personalities. Equipped with cutting-edge forensic technology, the team cracks one bizarre case after another by combining modern science with traditional investigative methods.
The central mystery running throughout the story is the “Bloody Butterfly” serial murder case. After every murder, the killer leaves behind a butterfly specimen, and the cases are mysteriously connected to the unsolved case in which the division’s former captain died twenty years ago.
