Ten years ago, the "Rainy Night Butcher" case was hastily closed with the accidental death and stigmatization of detective Chen Kang. Ten years later, retired police officer Song Yuanfeng thought he could spend his remaining years in peace, but was forced to return to the scene of the crime - a series of serial murders that were highly similar to the old cases, with deadly provocations pointed at him, completely shattering his peaceful life.
As the investigation deepened, all the evidence strangely pointed to the long-dead Chen Kang. Song Yuanfeng partners with the keen criminal profiler Lin Xiaoyue (the daughter of the only survivor of Chen Kang's old case). In the process of tracking down the real murderer, he discovers that the "procedural justice" he firmly believes in may be hiding shocking lies and betrayal. The murderer seems to be Chen Kang's younger brother, whom he regards as his own brother - elite lawyer Chen Qiming.
Using blood as a chess piece, Chen Qiming carefully laid out a revenge game that spanned twenty years. He not only liquidated the "accomplices" of the year, but also dragged Song Yuanfeng into the abyss of ruin and forced him to face the devastating consequences of his "key testimony" back then. Driven by atonement and protection, Song Yuanfeng must make the final choice between law and personal relationships, truth and price.
This is not only a pursuit of crime and punishment, but also an inquiry about how people struggle to find justice and self-salvation on the ruins after the collapse of faith, carrying a heavy past.
