Plot: Jiang Xiaobai has regained his memories, and Tong Li cannot bring herself to face him. Separately, they confront the truths left unsaid for 10 years—about the band September, to which Jiang Xiaobai and Mu Xiyu dedicated their youth; about the love triangle between Jiang Xiaobai, Mu Xiyu, and Tong Li; and about the painful circumstances that brought the trio together and ultimately led to the terrible tragedy that occurred on the day Tong Li left for America