This book deals with one of the most mysterious languages of the Far North of Russia - the so-called Old Sirinek Language (OSL, self-designation of the speakers uqeghllistun). The language is part of the Eskimo family; however, its place in the family is unclear. According to some theories, this language is the last survival of a third group of Eskimo languages alongside Yupik and Inuit. Although OSL speakers were located in eastern Chukotka, in the same area as Siberian Yupik speakers, and fused with the latter to a high extent, the OSL retained deep structural, phonological, and lexical distinctions from all Yupik languages. In 1895 the language had 79 speakers, in 1964 it had approximately 30 speakers, and in 1988-1990 there remained only four people who still could speak it. The last speaker, Valentina Wye, the person whose language skills and patient efforts to share them made this book possible, died in 1997. The book contains practically everything collected on OSL by several Russian scholars - Ekaterina Rubtsova, Georgii Menovschikov, Nina Emelianova and Nikolai Vakhtin - during the 50 years from the 1940s to the 1990s, with small additions of data collected by other people. It consists of four main parts: (1) Introduction, in which the history of OSL description is outlined, its genetic affiliation with other Eskimo languages is discussed, and a brief comparison with Siberian Yupik Eskimo is given; (2) the main part of the book, giving folklore and other narrative texts in OSL with Russian interlinear translation and, for some texts, parallels from Siberian Yupik Eskimo language; (3) a small section presenting grammatical data on the language; and (4) a supplement where lexical data are presented as materials for a dictionary, ca. 2500 entries.[written in Russian]