From a young lady in the south of the Yangtze River to a soldier in Yan'an, Jiang Nianwan burned away her past, transformed into "Jiang Hua", and started a new life on the Loess Plateau. She turned the melody of the pipa into a coded blade and planned chess moves to defeat the enemy. Shen Zheming, a doctor studying in Germany, worked side by side with her, saving lives and healing the wounded during the war, and faced the test of trust and emotional choices together.
When the top-secret mission is issued, the old enemy reappears, and the two return to danger. This is not only a battle for intelligence, but also the ultimate showdown between faith and betrayal. The beacon fire spreads across the river, and the sparks set fire to the prairie fire. They use their wisdom and life to write immortal legends in the torrent of the times.
