A motion picture producer has press agent Jimmy Austin take Mary Callahan, a pretty shopgirl, to Europe. After an extensive publicity campaign, Mary returns to the United States as Maritza Callahansky, a Russian actress owning the crown jewels. To add support to her newly established identity, Maritza gives a party in a Long Island mansion in the rightful owner's absence. The owners return to find their home taken over by strangers and are about to call the police when it is discovered that they are the parents of one of the extras in the company.