Zhang Lan's fall and death at Yangqi High School twenty years ago and the school's band twenty years later seem to be unrelated events. Yu Mingqi, the deputy leader of the flute section of the band, and the other four people love reasoning. They accidentally broke into the small building and discovered a shocking secret. The originally unrelated clues are gradually connected together. Let's see how the four-person team escapes from the school that is gradually shrouded in conspiracy! From now on, you are Yu Mingqi who is helplessly drawn into the whirlpool. The uncertain future and fate are in your hands. Life or death, it's up to you!