Paris, 1418. The city is occupied by the Armagnacs, besieged by Philip of Burgundy. Caboche, a butcher's guild member and supporter of the Burgundians, wants to marry a young woman. To do so, he denounces his father, who is soon after murdered. The Grand Conétable of Burgundy also has his eye on Catherine, but will not be able to take her because Duke Philippe has fallen in love with her.
