Chen Shan makes a living on the streets by trading intelligence. Because he resembles BIS operative Xiao Zheng Guo, Japanese spy leader Huang Mu Wei kidnaps Chen Shan's sister Chen Xia so that he will have no choice but to do their bidding. To save her, Chen Shan undergoes special training and proves to be an exceptional spy.

Assuming Xiao Zheng Guo's identity, Chen Shan infiltrates the BIS headquarters in Chongqing and starts a mission where one small misstep could cost his life. As a Chinese citizen, Chen Shan never really wanted to betray his motherland. He meets Zhang Li, a woman with firm beliefs and slowly turns into a man who is willing to give up even his own life for the sake of his country.