It is difficult to overestimate the importance of military and political intelligence during a war: timely information received about the enemy’s actions largely determines the outcome of operations. In his book, Jorgensen talks about how the German intelligence services were formed and developed. Examines the organization of the network of Nazi spies and agents operating in Britain, France, the Scandinavian countries and the Soviet Union, their successes and failures, as well as the activities of the groups, the Red Troika and the Red Chapel, working for Soviet intelligence. The author pays special attention to the confrontation between intelligence services and the secret war between the two most important figures of the intelligence services of the Third Reich, Reinhard Heydrich and Wilhelm Canaris. Exploring the meaning and meaning of Hitler's spy machine, Jorgensen concludes that its history is primarily a testament to conspiracy, betrayal, double-dealing and treason, but also to heroism, intelligence, insight and composure.