The column that wound south out of the Alpine foothills was lean as a drawn sword and twice as sharp. Forty thousand men—yet each cohort drilled to stitch itself to the next like plates of a single cuirass—poured onto the Lombard plain in a surge of disciplined momentum. Villagers spoke of mailed ghosts emerging from morning mist, their standards glittering with the rising sun. Maxentius's couriers, racing north from Milan, arrived breathless in Turin only to learn that Constantine's vanguard was already encamped beyond the western walls. Speed, the emperor knew, could stun as surely as steel.