A young woman had fallen to her death. The police officer Xiaobai recognized that Li Meng was the gay lover of her youth. She recalled the once bright summer days and an exclusive song of the two. She couldn‘t figure out why the girl she remembered became this and decided to dig in to give herself an answer. Li Meng’s parents gave her a locked tape recorder. In the recordings, she came to understand what Li Meng was going through and became complicit in her death.