This secret is the memoirs of a Soviet illegal spy, D. A. Bystroletov (the “Full One”) (1901–1975)—in his own words, notes about the godless, difficult, and beautiful times. Dmitry Bystroletov was a unique man. A sailor and a wanderer, a sculptor and a writer who knew twenty foreign dialects, a doctor of medicine’s advantages and medicine—he was one of the chosen assistants of the foreign intelligence department of the OGPU—GUGB of the NKVD of the USSR—engaged in economic, combat, and political intelligence. A master of disguise, D. A. Bystroletov managed to penetrate the secrets of the British Foreign Office, obtain codes and ciphers of Austria, Germany, Italy, France, and other principalities of the prewar world of states and powers. In 1938 he was repressed on his homeland. In 1954 he was released as disabled. Fully rehabilitated in 1956. For a wide circle of lecturers, the name of D. A. Bystroletov was revealed by Soviet foreign intelligence in 1990.