Ten years ago, undercover policeman Jiang Chen was falsely accused of being a serial killer and imprisoned. Ten years later, he returned with scars all over his body and found that the real murderer was still at large and even continued killing people with the help of the police force. Former comrade-in-arms Lu Zhao secretly reopens an old case, forensic doctor Chen Yanqiu reappears, and hacker Lin Wu clears the data fog for him. The real black hand is hiding in the most glamorous corner of the system. When Jiang Chen tore off the mask of the real murderer with his own hands, he found that the face was exactly the same as his own shadow ten years ago.
