In Hua'ao City, a brilliant detective with a flawless track record faces his toughest case yet when a string of seemingly perfect murders shakes the city. With no evidence, no witnesses, and a killer who vanishes without a trace, he must race against time to uncover the truth. As hidden dangers lurk in every corner, the line between hunter and hunted begins to blur.

In the 1980s, when middle-aged Hu Bayi packs his belongings for one of his adventures, he finds an old photo, which brings his memory back to his college days in the 1960s. He then ...