At the Guangyuan Winter Banquet in the 23rd year of the Republic of China, Zhang Linlu received the notice from Jinan University and also made an engagement with her childhood sweetheart Shi Jing. It was originally a beautiful marriage, but it was torn apart when the flames of war broke out - a street rally was held to protect her, Shi Jing was arrested, and when the prison van drove away, she clutched the half-length pen he had given her and said goodbye to her in this life.
She stayed with their faith and transformed into the "Pearl", a military special agent, lurking in the enemy camp. After three years of sword fighting, she had long thought her heart was as hard as iron, but she bumped into him in the interrogation room, who was labeled a "communist criminal". The two sides of the iron fence looked at each other, half of the pen was hot in the palm of his hand, the past engagement had become a secret that could not be told, but the light in his eyes was exactly the same as that winter night...
