"Stand By The Union" by Oliver Optic is a historical novel written in the late 19th century. The book is part of "The Blue and the Gray Series," which explores the complexities of the American Civil War through the personal experiences of its characters. The narrative follows young Lieutenant Christopher Passford, who has just reached adulthood and is preparing to take part in the war that has divided the nation. At the start of the novel, the protagonist, Christy Passford, experiences a mysterious visitation at his home just before he departs for military service. After an unsettling encounter with a midnight intruder, it soon becomes apparent that unexpected complications arise when Christy boards the ship Vernon, where he discovers another young man claiming the same identity as him. This relative, revealed to be his cousin Corny Passford, has assumed Christy's name and rank to carry out a treacherous plan against the Union, putting Christy in a precarious position as he seeks to uncover the truth and defend his loyalty to the North. The opening chapters craftily set the tone for a tale of intrigue, duty, and the tests of character amidst the turmoil of war. (This is an automatically generated summary.)