In order to help the queen singer find the whereabouts of the original composer and lyricist of the hit song "The Saddest Thing", the senior executive of the record industry, Bo Han, and his assistant An Yiqi, with the mysterious help of music seniors Ji Ge and Mao Maonu, uncovered the sad love story of the couple K Zhang Zhekai and Cream Song Yuanyuan, as well as the love-hate relationship between the warm-hearted dentist Yang Youxian and the photographer Cindy who were implicated in the process.