Ying Yuan (Jin Yubin) is a high school student, introverted but likes singing very much, while her good friend Shanmin (Xu Zhi) is just the opposite, cheerful and lively, is the school announcer. One night, Yingyuan stayed alone in the music room to practice songs. When she went to school the next day, Shanmin found that Yingyuan was missing. When she was recording in the studio, she heard Yingyuan's voice, but did not find her friend's figure. The strange thing is that the others did not hear it, and the panicked Shanmin fainted and was admitted to the hospital. In the hospital, Shanmin was finally able to calm down and listen to Yingyuan tell her story. It turned out that Young-eon was dead, and even she didn't know why only Shanmin could hear her voice. Yingyuan asked Shanmin to help her find her body, because she didn't even know who killed her and where her body was. As a result, Shanmin and the ghost of his best friend embarked on a terrifying journey to find the truth.