Mr. Muggs Steps Out

Mr. Muggs Steps Out is a 1943 American film directed by William Beaudine.

Now a chauffeur, Muggs brings the whole East Side Kids gang with him and puts them to work polishing cars. Muggs is instructed on proper etiquette, and when an engagement party is held for Brenda and her conservative fianc Virgil Stanley Brown, Muggs and the gang serve the food. At the end of the evening, one of the guests discovers that her diamond necklace is missing, and John accuses the East Side Kids of the theft. However, everyone recalls seeing a stranger at the party, whom Maisie now remembers as someone she met at Danceland, a dance hall on the lower East Side.Muggs convinces John not to call the police until he and the boys have had a chance to investigate. Maisie goes downtown to Danceland with Brenda, who dresses up like a gangsters moll in order to fit in. They meet with gangster Dips Nolan Gabriel Dell and learn that he plotted the jewelry heist with Diamonds, who was the stranger at the party. Nolan becomes suspicious when nave Virgil, who has followed Brenda to the dance hall, uses her real name and asks him to throw a fake fight so that he can prove his manhood. Nolan instead knocks Virgil out and kidnaps Brenda. ........

Source: Wikipedia