Private Carter Druse is a young man from a wealthy Virginia family who decides to join the Union army. His enlistment directly opposes the loyalties of his home state and his strict father. Stationed on guard duty above a valley where five Union regiments lie hidden, he faces the severe physical exhaustion of his watch. His position forces him to weigh his military responsibilities against his deep personal attachments.

Druse's Father is a wealthy, aristocratic Virginian and a staunch Confederate loyalist. Described as 'leonine,' he possesses a commanding, statuesque presence that masks profound emotional restraint. He embodies strict ideals of duty and personal honor, commanding his son to follow his own conscience even as they find themselves on opposite sides of the conflict. His stern demeanor hides the heartbreak of their family's division.

An unnamed Union officer conducts an aimless reconnaissance mission in the wild, walled-in valley. He possesses a spirit of adventure but proves highly susceptible to the optical illusions created by the bewildering terrain. He operates with discretion regarding the strange sights he encounters on his patrol.

The commander leads the Union forces operating in the area. He maintains a pragmatic focus on the military expedition and the safety of his troops hidden within the perilous terrain of the valley. He asks pointed questions to determine the tactical advantage of his unit's position.

A non-commissioned officer in the Union army tasked with checking on sentries. He represents the everyday reality and immediate accountability of military life. He presses for practical answers about events occurring near the camp.

Carter's ailing mother suffers from a grave condition that prevents her from being told about her son's decision to join the opposing side in the war. She represents the fragile domestic peace shattered by the national conflict. She remains off-screen, defined entirely by her illness and her family's desire to protect her.