In the 30-40s. Last century there was a fierce, dramatic struggle between the two strongest intelligence services in the world - Soviet and German. In many respects, the very existence of the USSR or Nazi Germany depended on the outcome of this struggle. The Soviet state security had a really formidable and very dangerous enemy - nevertheless, he was completely defeated on the fronts of the "invisible war." The author of this book, collecting material, worked mainly with foreign sources. Thanks to this, he managed to get unique information about our intelligence, operating in Germany and its satellites before the war and during the war years. For the first time, you will learn reliable information about the tasks of our agents, methods of transmitting information, ciphers and much more from the "secret kitchen" of Soviet foreign intelligence.