1942, Nanjing (Nanking). Following a series of assassination attempts on officials of the Japanese-controlled puppet government, the Japanese spy chief gather a group of suspects in a manion house for questioning. A tene game of "cat and mouse" enues as the Chinese code-breaker attempts to send out a crucial message while protecting his/her own identity.

In the spring of 1940 , former Chinese Kuomintang Vice Chairman Wang Ching-wei and the Japanese government to make peace , the establishment of the new National Government in Nanjing . Since then, the war against Japan entered a new " Three Kingdoms " period - Wang Jingwei, the Nanjing National Government , Chongqing Nationalist Government of Chiang Kai-shek , Mao Zedong led the Shaanxi-Gansu-Ningxia Border Region Government potential into the three pillars of co-ordination , mutual constraints . Wang Jingwei expand the three policy after taking office : Expand the army in the sphere of influence , clear Township Communist suppression induced strokes frustrated Chiang sent the military and political officials to join the cabinet . October 10, 1942 , Wang Jingwei government held a grand ceremony to celebrate the 30th anniversary of the establishment of the National Government , a Wang Jingwei government officials was shot dead , caused the Japanese side attaches great importance . Imperial Army secret long Takeda suspect that this series of assassinations planned by the Peking Communist Party leader in " the old fur cracked his organization would like to seize this opportunity . Responsible for sending instructions , "Old Devil " lurking in the counterinsurgency headquarters Takeda investigation and, therefore, the most likely to come into contact with telegraph five suspects were brought to the closed Qiu Zhuang - puppet bandits captain Wu Zhiguo , puppet the bandits corps commander of the attendants official white , puppet bandits Command translation electrical group leader Li Ning Yu , puppet bandits Command Chief transceiver Commissioner Gu dream , puppet bandits Corps Director of the Grand Council , gold light a fire . The survey period is only five days , Takeda must take a variety of means and even cruel torture to find the " old devil " . The five people under house arrest in order to protect themselves , but also deliberately watching around the other four , and hope that the " devil" as soon as possible and kick out so that they can safely leave Qiu Zhuang . Wu Zhiguo is also evil , white small gentle , self-sustaining Ning Yu calm , free and easy Gu dream spoiled , gold light a fire of doing things lukewarm , who among them is the real " old devil " ? Cut and thrust of the infighting , who can eventually escape Qiu Zhuang ?