Capital Secret.

In the mid-Ming Dynasty, Zhang Sheng and Yuan Su, two police officers in the Yamen of Beijing, were expelled from the Yamen because their colleague Cheng Yun beat a prisoner to death. They were at odds with each other. Later, Cheng Yun was killed mysteriously. The evidence pointed to the prison warden Ge Lin and the mysterious wealthy businessman Shen Kang. Can the two of them put aside their past grudges and fight back in desperate situations? Under prosperity, those unknown evils will eventually "surface".