Bone Prophecy: No Echo from Chang'an

During the reign of Yongjinghe, a widower who did not believe in ghosts and gods traced an unknown murder case on a snowy night, but accidentally got involved in a centuries-old secret art of bone prophecy, a secret war for imperial power, and the oldest truth between heaven and earth - he is the backside of light, a shadow, and the reflection cast by all human beings.