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.

Andy Lau Tak-wah
as Detective Dee

Li Bingbing
as Shangguan Jing'er

Deng Chao
as Pei Donglai

Tony Leung Ka-fai
as Shatuo Zhong

Carina Lau
as Wu Zetian

Richard Ng Yiu-hon
as Wang Lu (before face-lift)

Teddy Robin
as Wang Lu (after face-lift)

Liu Jinshan
as Xue Yong

Yao Lu
as Li Xiao

Wang Deshun
as Xiazi Ling