In 2025, when auxiliary police officer Cheng Yuan was tracing the truth behind the "accidental drowning" of his comrade Xiao Chen, he discovered that Xingyao Pharmaceutical, under the name of "drugs specially supplied to auxiliary police officers", had released chronic poisons to the auxiliary police group according to the police number, in an attempt to implement systematic elimination through "drug No. 0719". As the investigation deepens, Cheng Yuan, lawyer Su Xia, forensic doctor Chen Xiaoyu and others gradually uncover a twenty-year conspiracy - Xingyao Pharmaceutical and the ghost section chief Zhang of the police team select "experimental subjects" based on the police number suffix, and turn the auxiliary police's police number into a death number. Cheng Yuan's police number 0719 is the core target of this conspiracy.
From the car repair shop arson case to the theft of evidence from the police history museum, from the fraud in the special examination for transfer to the police to the attack and defense in the court, Cheng Yuan and others struggled to obtain evidence amidst institutional discrimination and threats of violence: the medicine bottles hidden in the secret compartment of Lao Zhou's car repair shop, the scarlet words in Xiao Chen's duty notebook, and the engine oil password of his father's purple clay pot. Together, they pieced together the chain of evidence for Xingyao Pharmaceutical's "poisoning according to the police signal". When Zhao Dayong's deathbed testimony revealed the cruel truth about Xingyao's "alarm signal is the experimental number", and when Su Xia's child became the first living evidence of "alarm signal poisoning", this war about dignity and survival finally ushered in the ultimate showdown in court.
Purpose: To pay tribute to all the "informal" guardians who silently protect justice