Prince Sigismund has devoted his life to the study of Socialistic principles as laid down in Payne's "Rights of Man." His daughter, Princess Lohra, is also a firm believer in these principles. Sigismund has collected an enormous treasure with which to finance a revolutionary movement of the Socialists. Dr. Carew, an American Red Cross surgeon, endeared himself to the family, and Sigismund, desirous of the safety of his daughter, arranges that she shall marry the doctor. The morning set for the wedding, the battle front moves up to the vicinity of the Prince's castle. Subsequently the ceremony is performed. The newly married couple leave the chapel and as the Prince turns for a last word with the witnesses, a shell enters, explodes and kills all of the party with the exception of the Prince and a piece so badly wounds him in the throat that he cannot talk. He staggers to the salon, where Dr. Carew keeps him alive long enough for him to write the word "Orisval." Princess Lohra feels that there is no happiness for her until she has accomplished the work her father had her promise to carry out for him before he died, and she and Dr. Carew, following up the clew that the dying man had given, finds a set of plans to the dungeons in which the treasure is hidden and they leave the castle in search of it. They succeed in finding the way into the chamber, and after Lohra has gathered the treasure Dr. Carew, realizing his wife's position, enters into her plans. During this action his Royal Highness, who is enamored of Princess Lohra, has brought his staff to Sigismund's castle, thinking of making it his headquarters. They find the dead Prince and on his person find a paper, which shows them his revolutionary move against the government. His Royal Highness goes for a walk in the grounds and sees the horses with which Princess Lohra and the doctor expect to make their journey to the meeting place of the Revolutionary Committee. At the same moment Dr. Carew and the Princess leave the treasure chamber and on their way to the horses they find the body of a dead spy, who in dress and appearance greatly resembles the doctor. Lohra is about to mount her horse when his Royal Highness tries to prevent her leaving. Carew hears her call and, rushing to her aid, overcomes the Prince. Lohra dashes away and Dr. Carew escapes. Guards hearing the Princess cry rush and fire at the retreating figure of Dr. Carew. Following him they find the body of the dead spy and believe they have killed the Princess' assailant. General Brunn and staff are attracted to the scene and the old general finding a button on the ground and later comparing it with an entirely different kind of button on the spy's uniform has his suspicions aroused. In the meantime Carew, far away, removes the beard he has been wearing, and as far as possible changes his appearance. He returns to the scene of the fight, shows his American passport to Brunn and treats his Royal Highness. While this has been going on Princess Lohra has been riding towards her gold and passes through scene after scene of the horror and desolation of war as it exists today in Europe. His Royal Highness is removed to the house and Carew finds on him a case containing the picture of his wife, Princess Lohra. While he is examining it, his Royal Highness regains consciousness and becomes enraged at his having the picture and orders him placed under arrest. Lohra reaches the meeting place of the Revolutionists, turns over to them the treasure, and word being brought in by a look-out that the troop of cavalry which was dispatched after her is in the vicinity, she quiets their fears by telling them it is an escort sent after her, leaves and rides away to be arrested by the soldiers. They bring her back to her home and in the garden she is met by General Brunn, who demands of her the name of the assailant of his Royal Highness. Upon her refusal to tell anything, he orders up a firing squad. As they have their rifles leveled, his Royal Highness, who has witnessed this action from the window, comes into the scene and, for his own purpose, takes Lohra from the soldiers and into the house, where he attempts to make lore to her. The Princess sends a message to the doctor, telling him to make his escape immediately, if possible, and she will meet him in some way at the American Embassy. A few minutes later Carew is brought into the room, and suddenly seizing a revolver from one of the guards, succeeds in escaping in the excitement. Lohra rushes to another part of the house, where she is followed by his Royal Highness. The Prince, in his mad endeavor to overcome Princess Lohra, brings on an epileptic fit to which he is subject and Lohra escapes by the window. Carew, although slightly wounded, succeeds in getting to the treasure chamber and later reaches the Embassy shortly after his wife. In the Embassy they find happiness under the protection of the Stars and Stripes.