This is a story about Rong Jinzhen, a hero of cipher on China's hidden front. Rong Jinzhen, whose parents passed away since his childhood, was raised by an elderly foreign missionary who taught him to interpret dreams. Jinzhen was naturally solitary, but her distant uncle Lili discovered that he was a mathematical genius and took him away from his old house to live with him. Jinzhen's fate underwent a transformation for the first time. And what changed Rong Jinzhen's fate once again was that he met his lifelong mentor Liseiwicz. Liseiwicz is a mathematics professor at Rong Jinzhen's university, and in fact, he is also a cipher expert. Liseiwicz discovered Rong Jinzhen's talent, and they two became mentor and apprentice. Liseiwicz taught Rong Jinzhen knowledge and became the closest person to Rong Jinzhen besides our family. Liseiwicz wanted to take him to study in the United States, but the war broke out and Jinzhen was accidentally injured and unable to travel with him. Liseiwicz had no choice but to leave Jinzhen and travel to the United States with his wife. Rong Jinzhen gradually returned to a peaceful life until Zheng's arrival disrupted it. His fate changed for the third time. Zheng took Rong Jinzhen to the mysterious 701 to be engaged in the decryption work of the hidden front. But Rong Jinzhen did not know that his opponent was his mentor Liseiwicz. From then on, a battle across the ocean and a game in the mist of ciphers unfolded......