After incredible toil, they stood on the summit, face to face with the astonished garrison. For a moment they paused to recover breath, then sprang furiously on their foes. The struggle was short, but desperate. Most of the Aztecs were put to the sword. Some were thrown headlong over the battlements, and others letting themselves down the precipice, were killed on the borders of a little stream that wound round its base, the waters of which were so polluted with blood that the victors were unable to slake their thirst with them for a full hour![358] Sandoval, having now accomplished the object of his expedition, by reducing the strongholds which had so long held the Chalcans in awe, returned in triumph to Tezcuco. Meanwhile, the Aztec emperor, whose vigilant eye had been attentive to all that had passed, thought that the absence of so many of its warriors afforded a favorable opportunity for recovering Chalco. He sent a fleet of boats, for this purpose, across the lake, with a numerous force under the command of some of his most valiant chiefs.[359] Fortunately, the absent Chalcans reached their city before the arrival of the enemy; but, though supported by their Indian allies, they were so much alarmed by the magnitude of the hostile array that they sent again to the Spaniards, invoking their aid. The messengers arrived at the same time with Sandoval and his army. Cortés was much puzzled by the contradictory accounts. He suspected some negligence in his lieutenant, and, displeased with his precipitate return in this unsettled state of the affair, ordered him back at once, with such of his forces as were in fighting condition. Sandoval felt deeply injured by this proceeding, but he made no attempt at exculpation, and, obeying his commander in silence, put himself at the head of his troops and made a rapid countermarch on the Indian city.[360] Before he reached it, a battle had been fought between the Mexicans and the confederates, in which the latter, who had acquired unwonted confidence from their recent successes, were victorious. A number of Aztec nobles fell into their hands in the engagement, whom they delivered to Sandoval to be carried off as prisoners to Tezcuco. On his arrival there, the cavalier, wounded by the unworthy treatment he had received, retired to his own quarters without presenting himself before his chief.