Xin Zitong, who left five years ago, returned to her hometown, reunited with Gu Xijue, met Su Ze, and reunited with her old best friend Hu Xiaoxia. But reality and memories have completely changed. She moves forward in confusion and explores the unknown. Whether it is to drink from the trickling stream that is within reach, or to climb the green mountains that reach into the sky. . . . . .