Jewel thieves Chico and Harpo Marx disguised as Groucho plan the perfect crime. Groucho appears as himself at the end in a police line up.
Harpo Marx
Nick
Chico Marx
Harry
Benny Rubin
Jewelry Store Manager
Joy Rodgers
First Woman
Art Gilmore
Himself - Substitute Host
Groucho Marx
Suspect in a Police Lineup