In January 1933, the Japanese army captured Shanhaiguan and occupied Chengde in March. The anti-Japanese situation in North China was precarious. The forces of many countries in Shanghai were in a stalemate and undercurrents were surging. Gu Pan, a special agent of Qingshan Military Academy, cooperated with Tianqiao Jie and his lover Tan Zhongwen to complete the task of his mentor Pu Cong, and was secretly arranged to complete the assassination mission of Koji Kamiya, the director of the Japanese Economic Department, alone. Gu Pan completed his mission with injuries, but was framed by Pu Cong and imprisoned. He was rescued by Wei Dong, an outstanding soldier of our party, in desperation. Under the guidance of Wei Dong, Gu Pan went through the test and entered the secret organization "Beehive" to try to find out why he was framed. As the truth was revealed, Gu Pan not only found the spy organization hidden deep inside the Kuomintang, but also came into contact with the dark and corrupt side of the National Government step by step. In the process of pursuing justice, Gu Pan gradually moved closer to the Red Revolution, and became a communist fighter with the code name "Seahorse", and became a partner with Wei Dong. Eventually, the "Beehive" was destroyed and the Japanese army's "Dark Day Plan" was uncovered.