During WWII Yang Haotian, a soldier of the New Fourth Army, is leading his fallen comrades: soldiers Feng Siyu and Xiaohu with hygienist Dou Hua'er. They meet Qin Yu, a National Army informant who is being pursued by the Japanese, at Misty Cloud Ridge. The two sides, with the help of the hunter's daughter, Sanxi, go from hostility to cooperation and work together to resist the dangers of the sky and fight against the Japanese. Using their respective strengths, the men succeed in stopping the Japanese plan to track and intercept them, buying precious time for the successful delivery of the information.