The Queen of France asks the curious Count of Saint Germain to give the Teardrop of Warsaw back its shine. If this pearl were to fade away, a terrible curse would strike the Monarchy. But the jewel has been stolen... and Nicolas Le Floch is in charge of the investigation.

The young count Louis Charles of Allas is discovered beheaded. Nicolas le Floch, who has been sent to Aquitaine to investigate, discovers that there are other victims. Bourdeau, la Satin and Semacgus are his partners on this dangerous mission.