Special Party Branch

Mao Jia Xuan and Shen Zhuo Yi are engaged in a secret mission to carry out a secret war, and both of them recognize themselves as the code name “Pang Defu”. Who is the real “Pang Defu” and what does this code name mean? The characters’ identities are reversed in multiple ways and the truth becomes confusing.
(Source: FarEastFilms.com; edited by MDL)