Adding a little spice to a waning marriage, Anne and Bob, a wealthy and well-connected American couple, move into a manor house in romantic Paris. While preparing a particularly luxurious dinner for sophisticated international friends, our hostess discovers there are thirteen guests. Panic-stricken, Anne insists her loyal maid Maria disguise herself as a mysterious Spanish noble woman to even out the numbers. But a little too much wine, and some playful chat, lead Maria to accidentally endear herself to a dandy British art broker. Their budding romance will have Anne chasing her maid around Paris and finally plotting to destroy this most unexpected and joyous love affair.

Anne and Bob are a couple who have just settled in Paris and have decided to hold a dinner in which high society will meet. At the last moment Bob invites his son from the first marriage so that there will be thirteen place settings at the table instead of twelve. By simple superstition, he decides to add a place setting and asks his maid Maria to pretend to be a rich Spaniard. But, the excess of wine and a suggestive conversation make that Maria and a dealer of English art are attracted. Anne does not approve of this romance and has the firm intention to stop it however.