In The Black Harvest young Ashby Marchbanks finds himself disillusioned with the regular Army in Missouri after it suffers a crushing defeat at Wilson's Creek during the Civil War. Forced to take the loyalty oath and return home in Howard County near Glasgow, he attempts to follow his father's footsteps and attend William Jewell College where he will labor over the Word of God. It's not long before Charles Jennison's Red Legs come to call, and after hanging his father and terrorizing his family, Marchbanks is shot and left for dead.

Ashby (or "Preacher") falls in with the infamous Captain Quantrill's bushwhackers, who fight battles on their own terms without the sanction of Jefferson Davis and the impromptu Confederate government. Preacher becomes well acquainted with Frank James and his younger brother Jesse. They fight together with many others who would become notorious in their own right under another violent young chieftain, Captain Bloody Bill Anderson.

This is all out war where outnumbered guerrillas wear stolen Federal blue and bushwhack their enemies in a war fought at close range, bristling with Navy Colts. Theirs is a war for survival on the bloody border where violence between Kansas and Missouri began long before Fort Sumter. A wild and compelling tale, it captures the complexity of the era, and evokes an epic all but lost to history. It was a time of violence, outlaws, and virtual anarchy. As the country became distracted by the accumulation of military defeats of the Confederacy in the South. Jayhawker Federals and Missouri Bushwhackers went head to head in an increasingly violent war.