Colonel Winslow, veteran of the Mexican War, hopes for a great future for his only son, Frank. At the outbreak of the Civil War, a recruiting station is opened in the Virginia village where the Winslows live. Frank, obsessed with fear and admitting that he is a coward, refuses to enlist. His father's humiliation is great and in his wrath he drives Frank to the office under threat of death, and the son joins the local company. The very first night he is assigned to picket duty near the Union front. He is terrified, throws down his rifle and flees. His family's negro, Mammy, gives him refuge in the kitchen and summons his mother. The latter is comforting him when the colonel, puzzled by her absence, comes to look for her and discovers Frank. The colonel then goes to the army and becomes Private Winslow in the company which his cowardly son deserted. Meanwhile, Frank hides in the attic as a group of Union officers arrive and take possession of the house. As they discuss the weakness of one of their positions he listens. A plan formulates itself in his mind; he casts away his fear and obtains the plans by surprising the officers while they are unarmed. On a horse he rides to the Confederate commander, having made his escape in the blue coat of a northern sentry whom he had knocked unconscious. As he gallops ahead of his pursuers he starts across a bridge commanded by the fire of his father, who is on picket duty at the time. Seeing only the blue coat Colonel, or private, Winslow fires. His aim is true and horse and rider topple into the river. Frank, however, though wounded is able to get ashore and deliver the plans to the commander. An attack is ordered and the northern army routed. Father and son are reunited after the battle.