During World War II, a plane transfers Bulgarian antifascists from the USSR to Bulgaria. They jump with parachutes. The eighth paratrooper heads a guerilla group. In the group, there are doubts about the existence of a traitor. Initially, an innocent person is accused, but later the real traitor is caught and killed. Still, the most dangerous enemies of the guerillas are the colonel and the troops stationed in the nearby village. The battle between them and the guerillas is won by the latter who continue to fight for their cause.