A strategic series of Civil War battles take place in the Shenandoah Valley between Union General George Armstrong Custer and Confederate Colonel John Singleton Mosby, known as the Gray Ghost for his stealth and elusiveness. Mosby’s cavalrymen, known as Mosby’s Rangers, continually outsmart the much larger enemy forces in a sequence of raids, which enrages Custer and eventually creates a fierce cycle of revenge between the two men.