Zhang Jian-He, a shy and introverted cartoonist, is in a relationship with his beautiful and traditional girlfriend, YaShi. One day, during an unfortunate altercation, Zhang Jian-He accidentally kills his best friend, Chen-Jun. To hide the crime, Jian-He meticulously cleans up the blood and any evidence, devising a unique and creative method to dispose of Chen-Jun’s body. Soon after, Jian-He uncovers a startling truth: Chen-Jun had been having an affair with YaShi all along. This revelation leaves Zhang Jian-He devastated, feeling betrayed by both his closest friend and the woman he loves. The narrative then introduces a serial killer named Jia-Ming, who had murdered his father as a minor. Disguised as a police officer, Jia-Ming resumes his killing spree after being released from prison and eventually connects with Zhang Jian-He through an online instant messaging platform.