On the eve of the liberation of New China, Xu Tian, a small policeman of the Baizhifang Police Station, accidentally participated in the cause of the Communist Party of China to peacefully liberate Beiping in the process of investigating the murder of his fiancée Jia Xiaoduo. In the face of the turbulent situation, the three brothers Jin Hai, Tie Lin and Xu Tian are in different positions, and when there is a fierce conflict between family affection, love, national interests, and personal beliefs, the three brothers who are like brothers and sisters make different choices and embark on completely different life paths. Xu Tian and Communist Party member Tian Dan met in a desperate situation, and the sense of mission brought the two together, Xu Tian chose to assist the Communist Party of China in the turmoil to achieve the peaceful liberation of Beiping and usher in a new world.