Lu Zheng pursues a serial killer in order to atone for his sins, but discovers in a new case that the murderer deliberately imitated the tactics of the cold case fifteen years ago. Interpol Captain Shen Yao initially regarded him as a troublemaker disrupting order, but the criminal psychology trap left at the scene forced the police to move forward, and she had to accept this talented wild child. As the investigation deepens, the silent forensic doctor Zhao Xueqin, the horrified witness Chen Yuan, and the retired detective Zhou Ming whose memory is collapsing, each hide secrets that are entangled in old cases. Lu Zheng peeled off layers of lies in the cobweb-like clues, and the murderer wandering in the dark was waiting for him to enter the last cycle of reasoning.
