The real reason why Shen Mo changed his career as a teacher was to investigate the "campus frame-up incident" that led to his sister dropping out of school and committing suicide seven years ago. Behind that incident stood a behemoth that integrated parental power, school corruption, and capital operations—the "Home-School Co-education Alliance." This is a gray interest network composed of problem parents, unscrupulous training institutions, and school insiders. It specializes in using conflicts between students to create trouble and make profits from it.