In 2007, 16-year-old girl Qiao Qingyu and her family, tormented by rumors about her sister Qiao Beiyu's death, were forced to relocate from their small county town of Shunyun to the provincial capital of Huanzhou. In order to quickly restore their family's normal life, Qingyu, with the help of her classmate Ming Sheng, began searching for the true cause of her sister's death.

In the 1980s, when middle-aged Hu Bayi packs his belongings for one of his adventures, he finds an old photo, which brings his memory back to his college days in the 1960s. He then ...