813

Robert Castleback is in possession of secret papers which could bring a certain prince to power under conditions which would make Castleback a ruling force in Europe. Master crook Arsene Lupin becomes aware of Castleback's bid for power and, in the interests of France, begins a search for the plans. At the same time, German agents are looking for the same papers. When Castleback is found murdered in his apartments with Lupin's visiting card pinned to his breast, suspicion points to the master crook. Following Castleback's murder, his secretary and a hotel porter are found dead. By mysterious messages, Lupin informs the public that he is innocent of the crimes, although the authorities believe him to be guilty. Lupin thereupon sets out to solve the mystery himself. By impersonating an officer of the law and dodging his enemies successfully, he aids the police in catching the real criminal and, after making his identity known, escapes the net thrown out for him.