After the September 18th Incident, the Japanese invaders built a military fortress known as the "Oriental Maginot Line" on the Sino-Soviet border. Anna, the Chinese adopted daughter of a Soviet general, sneaked into Northeast China to investigate the fortress, but was unfortunately captured by the Japanese army. The Northeast Anti-Japanese United Army sent investigator Wenlong to rescue Anna. Magician Gao Xiaozhuang, hunter Hu Dazhuang, female agent Tan Zhuoru of the National Army, and Northeast Army officer Wei Kunning and others participated in the rescue. After Wenlong rescued Anna from the labor camp of Hutou Fortress, Japanese officer Koizumi Kiyoshi of the labor camp led his troops to pursue her. Wenlong originally planned to send Anna out of the Sino-Soviet border in the northeast, but the Japanese army blocked the border in advance, so Wenlong changed his plan and decided to send Anna to the interior. Anna had photos recording the atrocities and secrets of the Japanese army. In order to avoid leaks, the Japanese army sent Abe Hiroshi to participate in the arrest. In the process of escorting Anna, Wenlong led everyone to destroy a series of military facilities such as the Japanese railway and drug factory, and found a large number of evidence of the Japanese army's invasion of China. In order to protect the evidence of Japanese crimes in our hands, Hu Dazhuang, Tan Zhuoru, Wei Kunning and others died one after another. After a desperate battle with the Japanese army, Anna was finally sent to a safe place.