The general theory of their action may be explained in the following propositions:Ren rolled down the roof to a long ledge that the light had shown him. If he could run along that he could gain the next house, and go a deal further. Then he might slip down another ladder, and so through a sleeping household to safety. He rocked unsteadily over on the ledge with his feet hanging perilously over the parapet; the next instant one of the police officers, at the risk of his neck, was upon him. Ren would have wriggled for his knife, but he dared not move."Soldiers discovered inhabitants of the suburb Saint Pierre in the cellars of a brewery, and killed them on the spot.