It was then that Ulpius, passing cautiously along the least-frequented streets, gained unnoticed the place of his destination. A thick vapour lay over the lonely and marshy spot. Nothing was now visible from it but the dim, uncertain outline of the palaces above, and the mass, so sunk in obscurity that it looked like a dark layer of mist itself, of the rifted fortifications. A smile of exultation passed over the Pagan's countenance, as he perceived the shrouding and welcome thickness of the atmosphere. Groping his way softly through the thickets, he arrived at the base of the wall. For some time he passed slowly along it, feeling the width of the different rents wherever he could stretch his hand. At length he paused at one more extensive than the rest, drew from its concealment in his garments a thick bar of iron sharpened at one end, and began to labour at the breach. Chance had led him to the place best adapted to his purpose. The ground he stood on was only encumbered close to the wall by rank weeds and low thickets, and was principally composed of damp, soft turf. The bricks, therefore, as he carefully detached them, made no greater noise in falling than the slight rustling caused by their sudden contact with the boughs through which they descended. Insignificant as this sound was, it aroused the apprehension of the wary Pagan. He laid down his iron bar, and removed the thickets by dragging them up, or breaking them at the roots, until he had cleared a space of some feet in extent before the base of the wall. He then returned to his toilsome task, and with hands bleeding from the wounds inflicted by the thorns he had grasped in removing the thickets continued his labour at the brick-work. He pursued his employment with perfect impunity; the darkness covered him from observation; no one disturbed him by approaching the solitary scene of his operations; and of the two sentinels who were placed near the part of the wall which was the centre of all his exertions, one remained motionless at the most distant extremity of his post, and the other paced restlessly backwards and forwards on the rampart, singing a wild, rambling song about war, and women, and wine, which, whatever liberty it might allow to his organs of perception, effectually hindered the vigilant exercise of his faculties of hearing.