Wealthy Anne Fredericks (Toni Collette) and her husband, Bob (Harvey Keitel), decide to throw a lavish dinner at their manor house in Paris for 12 of their sophisticated friends. When Anne realizes there are 13 place settings, she finds to her dismay that Bob invited his son at the last minute. Because having 13 to dinner is incredibly bad luck, she has to add a woman to the guest list. With no time to spare, Anne convinces her maid, Maria (Rossy de Palma), who reluctantly agrees to pretend to be a guest.

When one of their guests, David Morgan (Michael Smiley), takes a shine to Maria, Anne is aghast, especially when it develops into a relationship. Overjoyed at the turn her life has taken, Maria couldn't be happier, while Anne wonders if she should let David know that in fact, he's dating the maid.