Dee, the detective serving Chinese empress Wu Zetian, is called upon to investigate a series of strange events in Loyang, including the appearance of mysterious warriors wearing Chiyou ghost masks, foxes that speak human language and the pillar sculptures in the palace coming alive.

During the Late Tang Dynasty, a manor is invaded by a demon cat and a sense of unrest befalls the capital of Changan. A poet is charged with investigating the case and meets up with a monk. The two work together and pull apart the thread of clues to reveal a history of truths leading to the events.