1935, Peace Hotel: Mysterious guests gamble their lives during ten days. In 1935, when Manchuria has been occupied, patriot Wang Da Ding investigates an opium cream that is supposed to enter the market soon, and checks into the Peace Hotel. There he meets the returnee patriot from overseas and doctor Chen Jia Ying. While Jia Ying studied medicine in Japan, she found out that Japan is currently testing biological weapons in Manchuria in order to speed up their invasion of China. She now cooperates with the anti-Japanese squad, who is trying to locate the laboratories of the Japanese, and helps them with her medical knowledge. However, the Peace Hotel has already been encircled by the Japanese. In order to avoid being investigated by them, the two strangers Da Ding and Jia Ying pretend to be a married couple. A battle of wits between the two and the Japanese ensues.