Everyone has a blind spot, but only a madman dares to stare into it.
Five years ago, criminal psychologist Qi Lianyin mistakenly profiled a police officer, resulting in the death of a police officer and self-imposed exile.
Three years ago, ace detective Shen Jingye was suspended due to the "Butterfly Effect Case" and later died in the line of duty.
Now, "The Butcher on a Rainy Night" has reappeared, with techniques, timelines, rituals - all the details provoking Qi Lianyin's professionalism, and also provoking Shen Jingye's death.
This is not a simple serial murder case. The murderer is playing a game, he is waiting for the person who can see through him.
And Qi Lianyin gradually discovered that the person the murderer was waiting for might not be him.
Maybe it was the "dead" Shen Jingye.
Purpose: Humanity and Redemption