Description：The story takes place in 1984. Ma Dong (played by Hu Jun) is a national security scout. He was sent to the Military Industry Factory 202, lurking there to ensure the smooth development of the "Blue Fish" nuclear submarine. At the same time, a group of evil foreign forces are eyeing the confidential drawings of nuclear submarines, and the spies they sent are also hiding in Factory 202. At Factory 202, Ma Dong met his good friend Chen Qiqian (played by Zhao Lixin), and the factory flower Feng Shuya (played by Zuo Xiaoqing). Chen Qiqian has been pursuing Feng Shuya, and as time goes by, Feng Shuya gradually falls in love with the upright and reliable Ma Dong. However, Ma Dong's special identity prevents him from confessing his feelings for Feng Shuya. In the misunderstanding, Feng Shuya married Chen Qiqian in anger. What she didn't know at this time was that Chen Qiqian was killed by the recipient and had already