Professor Dooley takes home a duck from his research laboratory as a toy for his son, but soon finds out that it lays golden eggs.

When Madame Adelaide Bonfamille leaves her fortune to Duchess and her children—Bonfamille’s beloved family of cats—the butler plots to steal the money and kidnaps the legatees, leaving them out on a country road. All seems lost until the wily Thomas O’Malley Cat and his jazz-playing alley cats come to the aristocats’ rescue.