Shanghai, 1940. Ding Yi (Zhang Yishan) and Gu Yangshan (Han Dongjun): one is a bit-part actor with the Chaosheng Troupe, eking out a living in the Shanghai concessions by impersonating the blind code expert Li Yuesi; the other is a Juntong agent recently returned from overseas, who accidentally kills Li while trying to stop him from working for the Japanese. From then on, the two are bound together. Gu Yangshan goes along with the situation and hires Ding Yi to keep impersonating Li Yuesi, intending to sabotage the Japanese army's code research program. Ding Yi is swept up in this unexpected turn of events, while Gu Yangshan fights alongside him as his
