'The Cause of Darkness' is the story of a 16-year-old boy named Teddy Miller set during the last full-year of the American Civil War. Teddy lives with his father and brother in the Shenandoah Valley of Virginia. They lead more-or-less normal lives even while the War rages around them. But everything changes when their farm is burned, and Teddy’s father is arrested and sentenced to hang for espionage. Teddy’s single-minded quest to save his father reads like a grand adventure, full of gun fights, horse chases and 19th century justice. There is even a beautiful Pinkerton detective who plays a major role in Teddy’s exploits. But nearly all the adult characters act solely in their own self-interest and few have Teddy’s welfare at heart. Left without adult guidance, Teddy takes actions to save his father which have consequences that he cannot fully comprehend; and it is the consequences of these actions that drive the novel to its conclusion.