The story takes place in Shanghai at the end of the 1910s. Hu Yang is on his way to Shanghai when he suffers from memory loss and is imprisoned. He is rescued by two siblings, Li Mingyue and Li Minghui, who have no regard for life and death. He was then told that he had to go to Shanghai to carry out a "secret mission" and that he had to get in touch with other "contacts" related to the mission in order to complete it successfully.