Peggy, a young department-store salesgirl, finds a box with a costume and an invitation to a masquerade ball at the home of wealthy Austin Pratt. On the night of the ball she puts on the costume and attends. She meets Pratt's son George, who falls for her and wants to marry her. George's father, hoping to dissuade his son from a reckless marriage, suggests that Peggy live with the family for two months. Meanwhile, Peggy's former boyfriend Hall, whom she had broken up with because of his laziness, has seen the light and returned to claim Peggy, only to find her living with the Pratt family. Complications ensue..