Based on the operetta of the same title by Johann Strauss.
The wife finds out that her husband is constantly cheating on her. Their mutual friend and acquaintance Falk decides to play a joke on the poor married couple. He gives his maid, who dreams of becoming an actress, an invitation ticket to a masquerade ball and a “bat” costume so that she can “bewitch” the hapless womanizer. The wife hears this conversation and decides to also go to the ball in order to make her husband fall in love with her again, but only under a mask.