Once a famous lawyer, Hector Loursat de Saint-Mars lives in his remote provincial estate and has become an alcoholic since his wife left him eighteen years ago. He did not care for his daughter, Nicole, who was raised by a servant. One night, an explosion shakes the house. Hector discovers the corpse of a man in the attic. The victim is a fugitive from justice who goes by the name of Gros-Louis.