Lin Xia, a second-year high school girl, is disqualified from the re-selection because her hosting election draft is completely identical to a prematurely leaked version. With the roster about to be sealed, she refuses to let misunderstandings define her and decides to investigate the truth with evidence. Assisted by her classmate Zhou Yan, the two trace step by step through a mysterious USB flash drive, a broadcasting station recording card, missing pages in the registry, and library print records. Cheng Lu, the study commissioner, who listened to Lin Xia's rehearsal without authorization due to competitive pressure, also bravely admits her mistake in the face of facts. As new clues emerge, doubts point to the complex circulation of materials. Teachers and students verify the evidence, and ultimately revoke the direct accusations against Lin Xia, granting her a renewed opportunity for re-selection.