The story happens in the critical stage of the war against Japanese aggression when Wang Jingwei puppet regime betrays the country and surrenders to Japan. The President of Shanghai Ming’s Company Ming Jing secretly gives financial assistance to the Communist Party, but her younger brother Ming Lou is working for Military Statistics Bureau (MSB) of KMT. On his way to Hong Kong, their youngest brother Ming Tai is abducted by senior official of MSB. Ming Tai is forced to hide his identity and receive secret training, after which he becomes a secret agent in Shanghai Station of MSB. In the following missions, Ming Tai develops trust and romance with Cheng Jinyun, a member of Communist Party action team. Under the circumstances in constant changes, two young people will face challenges posed by fate.