In the muddy streets of the Tang Dynasty's capital, authorities discover the body of a murdered child. In his left hand, the boy clutches a letter accusing his parents of a terrible crime. In his right hand is a small wooden carving of Leigong, the God of Thunder. Over the following weeks more children are discovered, each holding a letter in one hand, a statue of Leigong in the other.
Since leaving the Emperor's police force, Ming has led a dull life. He spends his days tutoring young scholars in the Confucian texts, raising his children and tending to his dying wife. But when the murders threaten to plunge the city into chaos, Ming is called upon to rejoin the Gold Bird Guard and stop the terror.
Ming is no stranger to crime, but this time he isn't tracking a bandit or a thief. To find his killer, Ming must navigate the dizzying world of Chinese bureaucracy and intrigue. He must also learn about Leigong, a fearsome god that wields nature to punish those who harbor secret crimes. As Ming pushes deeper into this mystery, he discovers he must go one step farther. He will have to look into his own past, and confront the sins he has spent years trying to forget.