A Federal spy operating within the Confederate lines, meets Hallie Coburn, a fair Southern girl, with whom he falls in love. The Spy enters into the social life. At a garden party he again meets Hallie and they become better acquainted. Gradually their acquaintance ripens into love. Hallie innocently takes the spy into the Confederate camp where he obtains needed information. Suspicion however has become directed towards him and on his attempt to invade the camp alone at night is discovered by one of the pickets and captured. He, however, makes a logical explanation of his presence in the camp and is allowed to depart. As he is leaving the spy unconsciously gives a military salute and the commander looks after him with a worried look on his face and a feeling that he is not what he claims to be. Hallie is summoned to military headquarters and told that her lover is suspected of being a spy. She indignantly denies the accusation and proposes that she will wring a confession from him and, if guilty, give him over to the military authorities, but resolves to herself that even if guilty, she will aid him to escape. With this resolve in mind she goes out to find the spy. In the meantime the spy's room has been searched and incriminating evidence found and his capture ordered. Hallie meets her sweetheart and tells him of the suspicion pointed towards him and asks if he is a Federal spy. He admits his identity but love proves the conqueror and Hallie determines to aid him to escape and suggests a plan. Her ruse succeeds and the spy, by swimming under water, alludes the soldiers who have been sent to arrest him and makes his way into the Union lines. At the end of the war he returns to claim her as his bride.