When the future empress Wu Zetian's two courtiers die in a mysterious fire, she gets Di Renjie, a former detective and rebel, released from prison to solve the mystery of the fire.
An undercover agent is assigned by his corrupt chief to infiltrate a rival department and sabotage their investigation of counterfeit currency. What he discovers is the counterfeiter's real plan. To overthrow the capital. Not by flooding it with funny money, but with an army of undead.
