Modern forensic examiner Shen Yan travels through time to the Great Yin Dynasty and becomes the director of the Secret Records Bureau, responsible for handling the most unspeakable secrets in the entire realm. Armed with criminal investigation techniques so extraordinary they seem almost supernatural, he cracks seemingly impossible cases one after another. A bowl of clear water exposes alum in a blood test for determining parentage; a corpse with no external injuries but shattered internal organs reveals the real murderer; and an account book that cannot be burned drags half the imperial court into the scandal. His appraisal score rises from black iron to diamond, while every official in the court waits for him to fail. But the more he investigates, the more something feels wrong. Every case seems suspiciously easy, and every opponent appears to be waiting for him to make a move. Until the Shen family's massacre from sixteen years ago comes to light, and he finally realizes that every case he has investigated was part of a script someone wrote long ago.