Criminal Investigation Bureau Special Cases Unit

Gu Zheng, Assistant Minister of the Dali Temple, joins forces with Shen Tang, daughter of a former imperial physician, Zhao Tie, a retired frontier army commander, and Chen Mingyuan, a paperwork genius, to form a special investigations unit in the Criminal Investigation Office.

They take on a series of bizarre cases, from bones crying out for justice to imperial examination fraud and a snake infestation at the examination compound...

What they don't know is that every case points to the same vast conspiracy.

"We're not investigating cases. We're investigating the human heart."