He next appeared during the German invasion of Russia, running networks of partisans behind German lines. He discovered that his radio operator was a double agent for the Germans and so fed him false information that confused the Germans. According to one legend, at "Yelnya", Karla caused the Germans to shell their own forward line (presumably a reference to either the Yelnya Offensive during the first Battle of Smolensk, or the second Battle of Smolensk).