Zhou Yan, the only survivor of the family massacre, was reviled by the entire Internet as a murderer, but he survived in a surveillance blind spot. The new team leader Lu Zhao was ordered to reopen the case and found that all the dead were related to a buried human experiment twenty years ago. Forensic doctor Su Li's abnormal autopsy data, underground businessman Han Jin's black market transactions, and funeral director Chen Banshan's old files all point to an organization that has never been exposed. The murderer is hiding in the shadow of power, waiting for the next living sample to appear.
