The film tells the work of Soviet military experts who arrived in Vietnam in 1965. The script is based on the memories of Soviet missileofficers who were called in to train the Vietnamese soldiers to work on theS-75 Dvina air defence systems. The prototypes of the main characters were Sovietofficers FyodorIlinykh and Boris Mozhaev.
The systems, used during the warin Vietnam, were capable of helping against single targets and clusters, and low-flying and high-speed targets. They were also used to suppress the operation of anti-radar missiles such asShrike.
Veteransof the air defense forces who participated in the military operations of theSoviet Union also attended the film-making team. At the academy, filmmakersshot instructional videos to assist participants in the filming process forlater production./.