Anne and Bob are a couple of Americans who have just settled in Paris and have decided to hold a dinner in which to gather members of the American and Parisian high society. She discovers at the last moment that the son of her husband’s first marriage has also been invited, so that the dinner has thirteen cutlery. By simple superstition, she decides to add a covered fourteenth and asks her maid Maria to pose as a rich Spanish woman. But, the excess of wine and a suggestive conversation make Maria accidentally fond of an English art dealer. Anne does not approve of this romance and has the firm intention to stop it.