The book reveals new facts unknown to the reader related to the writing of the novel “How the Steel Was Tempered.” For the first time, a detailed analysis of the pages of the novel is carried out in comparison with Nikolai Ostrovsky’s letters to his family and friends, the possibility of Nikolai Ostrovsky’s acquaintance with the Komsomol leader Taras Kostrov is examined in detail, and the version of Nikolai Ostrovsky’s collaboration with the writer Arkady Gaidar is considered. The work of a writer broken by illness is traced, the biography of Nikolai Ostrovsky is analyzed, which in many ways, it turns out, does not coincide with the fate of the hero of the novel Pavka Korchagin.