During the Great Patriotic War, the Soviet people heroically defended their homeland. An invisible war unfolded on the fronts, in our rear and in the enemy’s rear, the war of Soviet and German intelligence. This novel tells how a symbiont, a hardened saboteur of the German regiment Brandenburg 800, entered the consciousness of a simple Soviet guy. How they came up with the idea of who to help, what they did together for the victory of the Soviet people!