The Song of Yu Xian is a long-lost musical score in the martial arts world. According to legend, playing it can change the weather and make gods and ghosts cry. Legend has it that playing it can bring back memories, lead to a marriage, create a dream, and trap people in dreams according to the wishes of the piano master. This feather fairy song is actually a kind of illusion, a secret scroll that people in the martial arts world are looking for.