Their further exclamations were lost in a tempest of discordant shrieks, coming from the front and the rear, from the heavens above, and, as they almost fancied, from the earth beneath. They looked northward, towards the pyramid,--the whole broad street was filled with barbarians, rushing towards them with screams of anticipated triumph; they looked back to the lake,--the causeway was swarming with armed men, who seemed to have sprung from the waters; to either side, and beheld the canals of the intersecting streets lashed into foam by myriads of paddles; while, at the same moment, the few pagans, who had annoyed them from the housetops, appeared transformed, by the same spell of enchantment, into hosts innumerable, with spirits all of fury and flame. "What says the king of Castile? What says the king of Castile _now_?" roared the exulting infidels. "Santiago! and God be with us!" exclaimed Cortes, waving his hand, with a signal for retreat, that came too late: "Cross but this devil-trap again, and--" Before he could conclude the vain and useless order, the drum of the emperor sounded upon the pyramid. It was an instrument of gigantic size and horrible note, and was held in no little fear, especially after the events of this day, by the Spaniards, who fabled that it was covered with the skins of serpents. It was a fit companion for the horn of Mexitli; which latter, however, being a sacred instrument, was sounded only on the most urgent and solemn occasions. The first tap,--or rather peal, for the sound came from the temple more like the roll of thunder than of a drum,--was succeeded by yells still more stunning; and while the cavaliers, retreating, struggled, one by one, to recross the narrow pass, they were set upon with such fury as left them but little hope of escape. If the rashness of Cortes had brought his friends into this fatal difficulty, he now seemed resolved to atone his fault, by securing their retreat, even although at the expense of his life. It was in vain that those few cavaliers who had succeeded in reaching him, before the onslaught began, besought him to take his chance among them, and recross, leaving them to cover his rear. "Get ye over yourselves," he cried, with grim smiles, smiting away the headmost of the assailants from the street: "If I have brought ye among coals of fire, heaven forbid I should not broil a little in mine own person. Quick, fools! over and hasten! over and quick! and by and by I will follow you."