Abstract: This article explores the questions associated with the latter three days in the novels “Princess Mary” saturated with dramatic events: duel with Grushnitsky, breach in friendship with Dr. Werner, Vera’s departure, farewell to Princess Mary. Special attention is given the text, referred to as narrative interlude, which reflects the night and early morning events before the duel. The text is comprised of a lyrical part (from 2 am on June 17 to Pechorin's exclamation “amusing and upsetting”); the story continues in reminiscences of the hero a month and a half later in a different stylistic reflection. The author examines literary motifs underlying the decision of Lermontov to describe the events of the night before duel using different genre and styles – lyrical confession and novel narration, and believes that one of the key factors for understanding Lermontov’s plot lies in replacement of Walter Scott's novels for Pechorin’s night reading (“The Fortunes of Nigel” with “The Scottish Puritans”). According to the author, the novel “Scottish Puritans” is similar to the finale of “Princess Mary”. For substantiating this thesis,, the article focuses on the original title of the novel – “Old Morality”, translated into French as “The Scottish Puritans” and into Russian – “The Puritans”. It is assumed that the meaning of Scottish title was understandable to Lermontov; thus the author suggests a congenial collocation – "the frail dust". Events of the finale should be comprehended as a purifying catastrophe; its artistic idea meets requirement of the time – describe birth of a Christian person as a new stage of spiritual evolution.