Undercurrents are surging in Linjiang City, and the mysterious organization "Shadow Alliance" is quietly weaving a web of evil - young women are missing one after another, bloody symbols appear on the corpses, and the shadow of death is cast over the whole city! Criminal investigation captain Xiao Yi, a cold and decisive knife in breaking the situation, joins hands with the thoughtful policewoman Lin Xiao to face the "zero evidence" dilemma: surveillance has been wiped out by hackers, witnesses have died strangely and suddenly, unknown biochemical toxins have been detected in the body of the deceased... The charred corpse code in the abandoned factory, the encrypted totem in the church murder case, the organ trade behind the transnational money laundering chain... Every step is a high-IQ game with a madman! When the identity of the undercover police officer was exposed and the core informant was brutally silenced, Xiao Yi was forced to launch the "Backlight Plan"-disguising himself as a black market broker and going deep into the enemy's nest. Countdown to 72 hours! The true identity of the shadow leader "Viper" is about to surface, and Xiao Yi's fiancée is fatally related to an unsolved case three years ago... As the truth is revealed, a cross-provincial encirclement and counter-encirclement and suppression of life and death begins on a rainy night! High-energy warning: All members are madly criticizing the villain, extreme reversal of the game within the game, and hard-core details of criminal investigation and forensics! Click to reveal the most chilling human trump card in this strangulation battle between good and evil...