Detective Guerchard (Lionel Barrymore) is hard at work tracking down the burglar Arsène Lupin, who has been stealing his way across Paris. When a robbery is reported at the home of Gaston Gourney-Martin (Tully Marshall), the police immediately suspect that Arsène Lupin has struck again and hurry over to Gourney-Martin’s. When they see a car speeding away from his house, they stop the car and find the Duke of Chamerace (John Barrymore) tied up in the back seat, claiming that he had been robbed. Guerchard doesn’t buy his story for a minute and suspects that the Duke is really Arsène Lupin, but when Gourney-Martin arrives, he verifies that the Duke of Chamerace is indeed the Duke of Chamerace.
The next day, Guerchard realizes that not only did he not capture Arsène Lupin, he didn’t even get any good evidence to help the case. And to top it off, his boss is putting pressure on him to capture Arsène Lupin within a week. When Guerchard gets a note from Arsène Lupin himself saying that he will be at a party thrown by the Duke of Chamerace, Guerchard decides to crash the party. During the party, the Duke steps into his bedroom where he finds the beautiful Sonia (Karen Morley) sitting in his bed, waiting for her dress to be fixed. The two begin to flirt, but neither one is who they say they are. The Duke really is Arsène Lupin and Sonia is actually a prisoner working for Guerchard to help nab Arsène. While Guerchard is hard at work snooping around, trying to get dirt on the Duke, several of his guests are robbed when a birthday cake is brought out and the lights are turned off.
After the party, the Duke and Sonia take a trip out to the country with Gourney-Martin. Since Gourney-Martin stores his most valuable things at his country home, the Duke thinks this will be the best place to rob him. But it turns out there is one thing that can stop the unstoppable Arsène Lupin — an electrified safe. Not willing to give up that easily, Gourney-Martin gets a letter from Arsène Lupin threatening to steal everything he has. Guerchard is called in, and even on his watch, Gourney-Martin is robbed blind. Guerchard does manage to nab several of Arsène Lupin’s partners in crime, but he doesn’t quite nab Arsène. The Duke and Sonia run off and begin plotting to steal the Mona Lisa. Through a series of tricky diversions, they do succeed, but not for long. Guerchard does catch up with them, but the Duke sees to it that Sonia is able to go free. However, Guerchard may have won the battle for Arsène Lupin, but he doesn’t win the war. The Duke makes a break for it and escapes to start a new, more honest life with Sonia.
Arsène Lupin is a great movie, very slick, sophisticated, and witty. Not to mention very risqué, just watch the scene where the Duke meets Sonia. And how can you go wrong with both John and Lionel Barrymore? I especially loved John Barrymore as the Duke/Arsène Lupin. He was so suave and smooth, it’s easy to see how his character got away with the things he did. This is another one that you’d probably enjoy if you liked The Thin Man.