The story takes place during the War of Resistance Against Japan, and the Chinese people who were unwilling to be humiliated were fighting tenaciously with the Japanese imperialist invaders.The crazy invaders established a blockade near Hainan Island in an attempt to cut off the ties between the people's armed forces on the island and the Chinese Communist Party on the mainland.In order to support the struggle of the islanders, the organization sent staff officer Tan Zhen (played by Gao Bo) and squad leader Zhang Ling (played by Shi Jiufeng) to break into the Leizhou Peninsula with radio stations in order to guide the progress of the armed struggle through radio waves.Their Coconut Bay is now under strict control by the Japanese invaders. Zhang Ling's wife Lin Xiumei (played by Ye Ye) endured her reluctance to support her husband to cross the sea. However, the two consecutive crossings of the sea were severely damaged, and the situation was very serious.In order to ensure the establishment of the radio station, Xiumei, as a party member, overcomes all difficulties and organizes the third crossing of the sea... This film is based on real events.