The book is devoted to the activities of the special services of Germany, Poland the USSR in East Prussia in the 1920-1940s. Was the rector of the University of Koenigsberg an agent of Soviet intelligence? What role did the Japanese consul in Königsberg play in covering the preparations for Germany to attack the Soviet Union? What work was carried out by the source of Soviet intelligence "Lux" surrounded by Gauleiter Eric Koch? These and other questions will be answered by the reader after reading this book.