This drama is set during the Anti-Japanese War and tells the story of Xiang Yuansheng, who was born into a family of a Kuomintang officer. His life was completely changed due to an unexpected trip to Shanghai. The story of him getting acquainted with Communist Party members Chen Hao, Luo Minmin, etc. After experiencing the test of life and death, he realized the transformation of his faith and finally became an outstanding soldier on the hidden front of the Communist Party. It shows the unremitting pursuit of ideals and beliefs of a generation of young people in the tide of the times.