Ning Caichen, a believer in harmony between humans and demons, challenges popular opinion by advocating for peaceful coexistence. When rumors of dark forces stirring emerge and an ancient evil spirit threatens to awaken, Cai Chen embarks on a perilous journey to prevent global destruction. Accompanied by Nie Xiaoqian, a fox demon he previously rescued, they venture into dangerous territories bordering human and spirit realms. As they confront overwhelming odds, Caichen and Xiaoqian must find a way to stop the impending wave of darkness that could annihilate humanity.