Collection of documents on the capture and execution of Polish officers in the USSR. For the first time, a set of documents identified on this topic is being published in the archives of the Politburo and the Secretariat of the Central Committee of the CPSU, the Ministry of Defense, the Federal Security Service, as well as in federal archives. Russian and Polish historians and archivists took part in the preparation of the collection. Documents relating to the execution of 22 thousand Poles in the USSR have a unique fate. They were deeply hidden in the archive of the Politburo of the CPSU Central Committee, and only the first person in the state had the right to open the "Katyn package." These documents were especially dangerous also because the Soviet authorities at the Nuremberg trials sought to blame the Nazis for this crime. But, alas, time passes, and any events will certainly find their own place in history, belonging only to them. So this time.