But the day of expected deliverance dawned at last. Five miles beyond the Brenne the dust-clouds of the approaching host were seen, and then the glitter of their lances and their waving pennons. They swam the river. They filled the plain below the town. From the heights of Alesia the whole scene lay spread under the feet of the besieged. Vercingetorix came down on the slope to the edge of the first trench, prepared to cross when the turn of battle should give him a chance to strike. Caesar sent out his German horse, and stood himself watching from the spur of an adjoining hill. The Gauls had brought innumerable archers with them. The horse flinched slightly under the showers of arrows, and shouts of triumph rose from the lines of the town; but the Germans rallied again, sent the cavalry of the Gauls flying, and hewed down the unprotected archers. Vercingetorix fell back sadly to his camp on the hill, and then for a day there was a pause. The relieving army had little food with them, and, if they acted at all, must act quickly. They spread over the country collecting faggots to fill the trenches, and making ladders to storm the walls. At midnight they began their assault on the lines in the plain; and Vercingetorix, hearing by the cries that the work had begun, gave his own signal for a general sally. The Roman arrangements had been completed long before. Every man knew his post. The slings, the crossbows, the scorpions were all at hand and in order. Mark Antony and Caius Trebonius had each a flying division under them to carry help where the pressure was most severe. The Gauls were caught on the cervi, impaled on the stimuli, and fell in heaps under the bolts and balls which were poured from the walls. They could make no impression, and fell back at daybreak beaten and dispirited. Vercingetorix had been unable even to pass the moats and trenches, and did not come into action till his friends had abandoned the attack.