The impoverished King of Eltwich-Haldmandt plans an alliance between his daughter, Princess Zavia, and Prince Sacholdt, of Murtavia. The Prince, who has never seen Zavia, flees the country, as the time for the ceremony approaches, leaving word that he must marry as his heart dictates. Zavia, impressed by the failure of her father's plans, comes to the rescue by offering to sell the royal jewels in a foreign country. By chance, Prince Sacholdt is a passenger on the same steamer and makes her acquaintance. Von Block, a fastidious thief on shipboard, is one day removing a cinder from his eye, holding his pocket mirror before him. He gets a reflection of Zavia in her stateroom inspecting the jewels. The flash of the mirror apprises Zavia that she is being watched and she later switches the hiding place of the jewels. Von Block's plans are temporarily thwarted. Leaving the vessel, Prince Sacholdt gives his name to Zavia as "Johann Schmidt," asking her to summon him if he can help her at any time. On her way to a jewel broker's, Zavia meets with an accident arranged by Von Block, who secures the gems. She fears she will disclose her identity by informing the authorities and recalls "Schmidt," who comes to her aid. In locating Von Block and securing the gems, "Schmidt" suspects Zavia's identity. He wires his country, authorizing a loan to Eltwich and Zavia is mysteriously ordered to return with the jewels. Later the alliance is renewed and Zavia finds, to her happy surprise, that "Schmidt" is the Prince.