A sensational investigation into the tragedy of 1937. A gripping thriller that sheds light on the darkest and most forbidden pages of the past. A new look at the causes and goals of the Great Terror. The true story of the struggle for power over the USSR, during which Stalin managed to defeat not only the party opposition, but also the state security agencies, which in the mid-1930s reached the peak of power: the OGPU actually controlled the country's economy and financial flows, government security and police, Special departments of the Red Army and the gigantic shadow empire of the Gulag, the judicial system and the execution of sentences, managed colossal funds, transferred the largest construction projects and industrial enterprises to its jurisdiction, carried out secret supervision over the country's top leadership - it seemed that real power was floating from the hands of Stalin to Yagoda and his clique that the true center of power is no longer in the Kremlin, but in the Lubyanka. How did Stalin manage to turn the situation in his favor? What allowed him to divide the security officers and force them to kill each other? Why did this grandiose purge actually meet no resistance and Stalin’s counter-coup was a complete success?.. Answering the most pressing and complex questions of Russian history, this sensational study, read like an exciting detective story, unravels the main mystery of the 20th century.