(uncredited)
At the end of the 15th century, two traveling minstrels Gilles and Dominique come to the castle of Baron Hugues. Gilles charms Anne, Hugues' daughter, while Dominique charms both Hugues and Anne's fiance. Gilles and Dominique are not really in love: they were sent by the Devil to test desperate people. But Anne is so pure that Gilles is caught in his own trap... How will they fight against the Devil?
Gilbert, poet and singer, is about to marry Lilette but deep inside himself he is not quite sure that she is the woman he needs. That is the reason why he has made up an imaginary woman, Frédérica" to whom he writes love letters, actual ones this time. When Lilette finds one of these, she sees red. Théodule, one of Gilbert's many friends, sets out the problem with the help of Claudine, his own girlfriend, posing as Frédérica. After Gilbert and "Frédérica" have played a phony breakup scene in front of Lilette, things seem to come right when... another Frédérica appears...
As her neighbor Rémi Courmont has told her off for making his ears bleed with Ravel's Bolero, a music piece she plays at full volume all the time, Anne-Marie decides to get even with him. She sets up a hoax with the complicity of her friend Catherine, who agrees to post as Remi's mistress to embarrass him. Just then, Niquette, Rémi's real lover, resurfaces.
