Francis, reigning prince of Hofgarten, wishes to unite his kingdom with the adjoining principality of Strelitzburg. To do this it is necessary for his nephew, Philip, to marry Stella, sister of the neighboring prince. She has been in a convent for years and her brother has no idea of her appearance. Philip, who has also been in Paris at school for fourteen years, receives a letter from Francis, telling him that if he should refuse to marry Stella before he is of age his allowance will be cut off. Frederick is anxious to have his sister marry Philip, as Francis has promised to redeem the state jewels, which he has pawned, if the marriage is brought about. Philip on receiving the letter is quite disconsolate, as he has learned to love another girl and has never disclosed to her his royal birth. However, he strikes upon a plan. He will send Richard Savage, an adventurous American, to pose as himself. His uncle, not having seen him for fourteen years, will not doubt the substitute's identity. Savage falls in love with Stella and is spurned, she insisting their marriage would be one of convenience rather than love. Meanwhile, Philip, in Paris, has declared his love for a girl of humble birth, and made known his origin. They decide to journey to Strelitzburg, as only eighteen hours remain before he becomes of age. Philip and Savage enter the throne room just as Savage and the princess are to take the vows. Then comes the unexpected. Philip's fiancée is the real princess and to save herself from a marriage of convenience, she substituted her friend, Helen Churchill of Philadelphia. Both prince and princess have sent Americans in their places and when this is explained, the bishop performs a double ceremony, and all ends happily.