Joe, the younger brother, comes home from the military school in the north and shortly after his arrival on the old plantation, Virginia secedes from the Union. John, the older brother, enlists with the Confederacy and Joe, choosing the North, is ordered to leave the house. Six months later John is commissioned to enter the Union lines and learn the enemy's plans but just as he is starting down the road his horse falls, throwing him to the ground and breaking his leg. Susanna, seeing the accident, determines to take her brother's place. She arrives at the Union lines and through a ruse, secures the desired information. The object of her visit is discovered and a detachment of soldiers is sent to overtake her. Hearing the pursuers and fearing capture, she hides on a railroad trestle until the Union soldiers pass by. After they have gone she drops to the ground and is about to make her escape when she is challenged by a solitary soldier, who, much to her surprise, proves to be her brother Joe. She finally persuades him to allow her to escape. When she has disappeared the Union soldiers return and Joe holds them back at the point of his gun while his sister reaches safety. Joe is arrested, taken to headquarters and sentenced to be shot. Susanna arrives home and reports the success of her mission. A few days later the family learns the terrible price that has been paid for the information secured by Susanna.
—Moving Picture World synopsis