The Chernobyl disaster occurred more than 30 years ago, but disputes about its causes, consequences and the organization of work to eliminate these consequences do not subside. Chernobyl revealed many problems that go far beyond the Chernobyl topic: ethical, environmental, political. The Soviet system as a whole and even technological progress itself were, in the minds of many, compromised by this accident. To answer the questions that arise in connection with Chernobyl, it is necessary to know what actually happened on April 26, 1986. This book is based on unique materials: interviews, articles and memoirs of academician Valery Legasov, one of the leaders in the liquidation of the consequences of the Chernobyl accident, who was the first in the USSR and in the world as a whole to analyze the consequences of the disaster and was the first to talk about them in detail. In addition to them, the book includes articles on the technological and political aspects of the disaster, written using both modern materials and previously unpublished archival documents. The book will allow the reader to form his own opinion about the Chernobyl disaster in spite of pseudoscientific theories and politicized populist schemes.