In an old community at night, the garbage sorting point should be the end of waste disposal, but it has become the starting point for uncovering shocking secrets. Cleaner Li Yuan, a hard-working middle-aged man who lives in poverty, accidentally discovered several pages of incomplete document fragments from a pile of "abnormal garbage" during a routine cleaning. The vague numbers, names and obscure instructions on the fragments were like a key, quietly opening the Pandora's box beneath his peaceful life.
At first, Li Yuan took the pieces home and tried to piece them together out of curiosity. However, as the jigsaw puzzle gradually became complete, the tip of the iceberg of a long-lasting corruption case suddenly emerged - it was an old case involving the loss of hundreds of millions of state-owned assets, involving many high-level officials, and even big shots who had "retired" after their achievements. Li Yuan realized that he had accidentally touched a huge and dangerous whirlpool.
When he anonymously submitted some clues to the police, the originally hopeless policeman Lao Zhou was keenly aware of the anomaly, and a secret investigation began. However, the forces of corruption are far more powerful and cunning than imagined. They penetrate every corner and try to erase all traces. Li Yuan was forced to get involved. He used his identity as a cleaner to collect evidence step by step in "grey areas" that ordinary people would not pay attention to, such as garbage sorting points, waste recycling stations, and even old archives, and became a key informant for the police to solve the case.
