What is the main conflict in The Boarded Window by Ambrose Bierce?

To contemporary audiences, Ambrose Bierce is known for his writings—journalism, essays, and short fictions—for his cynicism and his misanthropy, and for his famous disappearance into revolution- torn Mexico in 1913, an adventure from which he never returned. His literary reputation, however, rests primarily on his short stories of the Civil War and the supernatural. In both of these genres, Bierce explores his interest in bizarre forms of death and the horror of existence in a meaningless world. Shortly before his disappearance, Bierce also took on the monumental task of organizing his body of work into the twelve-volume Collected Works of Ambrose Bierce. In the second volume of this work, amongst the gripping Civil War tales which perhaps have brought him his greatest renown, Bierce chose to included the slight "weird tale" "The Boarded Window."