A woman's mysterious disappearance entangles a series of bloody crimes. Has the psychopathic 'Evil Ghost,' hidden for 20 years, been lurking nearby? Yu Na, a veterinarian working at a pig farm, vanishes without a trace during a nighttime walk. Clues point to the 'Evil Ghost,' a killer who committed five horrific serial rape-murder cases two decades ago. The gruesome ear-cutting method used in the crimes sends chills down the spine, yet the perpetrator seemingly vanished into thin air. Feng Taishan, a police officer haunted by the unsolved case, vows to unmask the 'Evil Ghost' and find Yu Na. Suspicion falls on Yan Huiru, the owner of the pig farm, and her sons—Zhang Xiaojun and Guan Xiaowei—whose eccentric behavior and hidden motives deepen the mystery. As the investigation hits a dead end, the killer remains hidden, their unfathomable evil looming large. But behind the truth lies an even bloodier and more sinister dark secret…