Anne and Bob, a wealthy, well-connected American couple, move into a manor in Paris. While preparing a luxurious dinner for sophisticated international friends, Anne discovers there are only 13 guests. So, she insists her loyal maid, Maria, disguise herself as a mysterious Spanish noblewoman to even out the numbers. Too much wine and some playful chat lead Maria to endear herself to a dandy British artbroker. Their budding romance soon has Anne chasing her maid around Paris, reinventing the truth and finally plotting to destroy this most unexpected and joyous love affair.