Adding a little spice to a waning marriage, Anne and Bob, are hosting a luxurious dinner when Anne realises there are 13 guests. Panic-stricken, she insists her loyal maid Maria disguise herself as a mysterious Spanish noblewoman to even out the numbers. But a little too much wine and some playful chat leads 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.