In a research station in the Soviet military area of Beregavoye, a gas was developed to destroy the armies of the enemies of socialism. However, the gas experiment got out of control and had to be shut down. The remaining smoke bombs reached us during the Soviet occupation of Czechoslovakia in August 1968. Later, during a conscription exercise for high school students in 1985, gas from a stray smoke bomb infected students. A small group of students struggle to survive with their infected, aggressive classmates, but also with the schoolmaster Sergei, a former Red Army special forces officer. The infected students become biting and killing beasts. They fight with saw, club and red flag.