In early 1945, the Second World War was coming to an end. The overall situation on the European battlefield had been determined, and the Asian battlefield became the key to determining the direction of the war. In order to deal a fatal blow to the Japanese invaders, the Soviet Union turned its guns and formulated a top-secret "Avalanche Plan". The premise for the implementation of this plan is to obtain all relevant military intelligence such as the deployment of Japan's "Maru-ichi Cannon", the combat effectiveness and quantity of the Kwantung Army as soon as possible. At this critical moment, an important figure was arrested. His name is Takahashi Hiroshi (played by Liu Yunlong), and he and his father Takahashi Toshio are both senior spies who have infiltrated the Soviet Union for many years. Another identity is Liao Fei, the reconnaissance staff officer of the Chinese Anti-Japanese Allied Forces. At a banquet, Takahashi Hiroshi was captured by the Soviets. Upon learning of the news, Kazuo Sakagami (played by Ao Hata), the head of the Kwantung Army Intelligence Department, hurriedly deployed a rescue. Under the dark night, the murderous spy war kicked off...