This article is devoted to the issue of the emergence of conspiracy theories and their existence in the borderlands; the research is focused on the western boundaries of the Russian Empire, belonging to the Polish-Lithuanian Commonwealth before its partition. The material relating to these territories enables to have a fresh look on genesis of "the conspiracy theories'" in society, on the one hand, to reflect on the peculiarity of the borderland as a special cultural space, and, on the other hand, to add specific characteristics of "conspiracy theories" of the borderlands to the list of contributory factors to emergence of conspiracy theories in society. Reference to the west borders of the Russian Empire enables to use the material related to the beginning of 19th century, which is important for further development of the conspiracy study in Russia. This article centers around the analysis of "The letters written by court counsillor Opytov to countess Starozhilova with historical overview of the political mood of the nobility in Volhynian governorate". Life of Volhynian Governorate at the beginning of the 19th century is reflected in the letters which contain the exposure of the Polish gentry's plot against the Russian stateness. The extent of the "historicity" of this document and the possibility of assessing the situation in this region based on so-called Opytov's evidence raise doubts. The performed analysis shows that Opytov's letter was a fiction aimed at a narrow circle of readers familiar with the situation in Volhynia and western regions in general. The text of this letter contains the encrypted conspiracy narratives, known to Opytov's contemporaries, which can become the key to understanding what type of text it is.