Documentary research “Ural Monster. Chronicle of the exposure of the most mysterious serial killer of the Soviet Union" (in two books) is dedicated to the real, but now completely unknown history of the abductions and murders of young children in Sverdlovsk in 1938-1939. The author carefully analyzes the course of the investigation throughout its entire length, reveals the flaws and shortcomings of law enforcement agencies and offers the reader his own version of the mysterious events, noticeably different from the official one.