"By Right of Sword" by Arthur W. Marchmont is a novel written in the late 19th century. The story centers around Hamylton Tregethner, an Englishman who finds himself entangled in a dangerous situation in Russia that involves mistaken identity, dueling, and political intrigue. As he adopts the persona of a cowardly Russian officer named Alexis Petrovitch, he navigates the complexities of his new life and the perils that come with it. At the start of the novel, Tregethner receives a letter from his friend Rupert expressing despair over a romantic relationship, which leads him to reflect on his own troubles. While waiting for a train in Moscow, he unexpectedly encounters a young woman who mistakenly identifies him as her brother, Alexis, who is in danger due to a duel he must face. This chance meeting propels Tregethner into a decision to impersonate Alexis to help protect him, diving into a web of espionage and personal courage forcefully intertwined with love and loyalty. The opening successfully establishes themes of identity, conflict, and ambition, setting the stage for a gripping tale of adventure. (This is an automatically generated summary.)