Gustav Mark Gilbert was an American military intelligence officer who received a degree in psychology from Columbia University in 1939. At the end of World War II, Gilbert was involved in the work of the International Military Tribunal in Nuremberg as a translator for the prison commandant and a psychological expert. Participating in interrogations of the accused and prisoners of war, the author of the diary tried to understand their true attitude to what happened during the war years and determine the degree of repentance for certain crimes. From the moment the charges were brought and until the sentence was carried out, Gilbert had free access to the accused. His technique consisted of casual, face-to-face conversations. After these conversations, Gilbert sat down to write his notes, which later turned into a diary, which became the basis of the research presented to your attention. The book is intended for a wide range of readers.