She never expected that the classmate who had passed by in high school now became a terrifying cold-blooded killer.As a gossip reporter, she was forced to return to the long-clogged past, peeling off her cocoons from her familiar faces and vague memories just to reveal the truth - how did the boy who once sat in the back of the classroom and smiled a little shyly, step by step towards darkness?As the clue gradually emerged, she began to realize that the most terrifying thing was not the identity of the murderer, but the secrets that no one wanted to mention in that forgotten youth.