The review covers K. Chekalov’s monograph on the problems of mass literature and the literary legacy of Gaston Leroux. The author chose one of the pivotal moments in the history of French literature: a transition period, which, according to Bakhtin’s law on borderlines and transitions, combines adherence to traditions as well as revision of the existing systems. This topic has so far remained unexplored by Russian scholars, just like the works of Leroux, whose role in establishing the genre of detective fiction is enormous. No research has been dedicated to his oeuvre in Russia. Only a meager share of his works has been translated into the Russian language. The choice of such a topic implies the relevance and novelty of the research. The purpose of the book is to create a solid basis for further exploration of this complex phenomenon, which determined the book’s structure, comprising six chapters and a closing summary.