In the winter of 1948, the Huaihai battlefield. The telephone operator Yuxiang (played by Huang Xiaolei) rescued the rural girl Yuxiang (played by Li Xiuming) who was about to hang herself during the mission. Yuxiang has nothing to do with her, and she is willing to accept her personally and tell her sufferings of being homeless.

Public Security officers investigate the robbery of a post office and the injury of a young woman.

Set in the early 1970s, enemy warships encroach the islands of South China Sea frequently. The Chinese Navy fights the enemy and protects the islands and people from invasion.