At the beginning of the war, the Germans throw their saboteur into the USSR. The landing is unsuccessful - the spy is captured by the NKVD. When trying to escape, a saboteur who turned out to be a Russian thief in law, accidentally remaining in the occupied territory, dies. In order to find the other spies involved in the operation, the security officers have to turn to the criminal's twin brother, a rural teacher. He takes the place of the deceased in the German intelligence network and enters into a deadly game....