Ambrose Bierce was one of the strangest phenomena of American letters. The adjectives used to describe his writing -- and character -- tend to have a rather uncomplimentary ring: "venomous," "vindictive," "paranoid," "rancorous," "malevolent"; yet few would deny his brilliance of intellect and style. About half of his fiction output consisted of stories of horror and the supernatural, a genre which appealed to his psychic constitution and may have...