Synopsis by Janiss Garza
The character of Arsene Lupin -- a Raffles-like French crook -- was created by Maurice Leblanc, who wrote a series of stories about him. A number of his tales were filmed during the silent and early sound era. Here, Wedgewood Nowell -- normally a supporting actor -- plays the mysterious crook of many disguises. Although he is a criminal, Lupin is loyal to France, and he finds a chance to serve his country when he gets wind of a mad plot by diamond king Robert Castleback (Ralph Lewis). Castleback wants to place an obscure prince on the throne of France, figuring that, as his chief adviser, he could have sway over the world's policies. A pair of German spies are also involved. While Lupin is trying to outwit them, Castleback is murdered and the crook is believed to be guilty. While trying to avoid arrest and solve the crime, Lupin dons a series of disguises. The craftiest is when he convinces the police that he is their highest official. A series of murders continues until Lupin is able to trap the guilty parties and ensure peace in Europe.