Plot summary: In the early and mid-1960s, a large number of postgraduate and undergraduate students, with Song Chao and Wu Yansong as the representatives, disappeared from the campus overnight under the recommendation of Professor Guo Zhuang, a famous aerodynamicist in China and deputy director of the expert group of the Ministry of National Defense. They went to the desolate river beach and accepted the historical mission assigned by the country: to design and build the wind tunnel urgently needed for the development of cutting-edge weapons such as aircraft, missiles, and rockets for the Republic.