Eternal Wave 密战 is a Chinese film set during the anti-Japanese occupation era starring Aaron Kwok, Zhao Li Ying and Zhang Han. It follows the main protagonist Lin Xiang who is a spy working underground to reestablish what was destroyed ruing the Battle of Shanghai. He meets a simple yet patriotic young lady who becomes his partner as they infiltrate the enemy as a couple. Apart from that, they cross paths with Liang Dong, a man whose motives are unclear.
Shanghai was known as the Paris of the East, with a bustling economy, in 1930. Behind the dazzling songs and dances, however, brutality and terror take over. The Chinese Army fought the Imperial Japanese Army valiantly from the Marco Polo Bridge Incident to the Battle of Shanghai.
The Japanese army destroys several media outlets among Chinese forces in the city, and even private radio stations from the United Kingdom and France are required to register in order to function. Zhang Lanxin (Akiyama Masako), a Japanese agent in charge of such activities, proudly boasts that only Japan-approved stations can thrive beneath the Shanghai sky. Then one day, Li Xia (Aaron Kwok) accepts the mission to establish a new communication system for his people.