The book is devoted to the study of the causes, internal logic and scale of the terror organized by Stalin in the 30s of the 20th century. The study is based on a huge number of printed sources: documents of the Soviet state and the Communist Party of the USSR, Soviet newspapers, memoirs of various people, books by other historians. Numerical estimates of victims of terror made by R. Conquest are often disputed. At the same time, the attentive reader will see that Conquest never misses an opportunity to check estimates in various ways and is very careful with the figures. Yet the most important part of the book is not the two or three numbers that are roughly estimated and questioned, it is the detailed tracing of the tragic events of the 1930s. Events that are fully documented.