He pointed out into the lake, and there came the brigantines, sailing in toward the city proudly, as if conscious of their victory. They brought to within a long bow-shot, and before coming to the piles which the Mexicans had taken the trouble to drive in all directions close to the causeway, thus showing that their spies had obtained information for them. Then their guns opened, and a murderous discharge belched forth at the defenders of the causeway. The shot crashed against the masonry, or tore lanes through the unfortunate natives, killing and maiming huge numbers. At the same moment the guns on the far side of the gap opened upon the barricade, demolishing the upper parts. "We must retire at once," said Roger. "We will recall the men to the next wall and make better preparations. Come, let us be going. To remain is to throw our lives away." There was a shrill whistle, and the natives began to retire, crossing the next gap by means of planks left for that purpose. Then they set to work to raise their barricade with bricks, women and children bringing the latter, while an attempt was made to obtain cover on the lake side. "We must do something to drive off the brigantines," said Roger, as he stood watching the men at work, and listened to the loud crashes in the distance, the sounds made by the attackers as they filled in the gap. "Come, Philip, or you Peter Tamworth, have you nothing to suggest? How can we keep them at a safer distance? They take us in flank with their fire, and while their ammunition lasts we are helpless. We must drive them off or relinquish the causeway." This, in fact, was obvious to all, for the brigantines had matters in their own hands. There was nothing to keep them from the outer face of the causeway save the piles which had been driven there, and those could only be placed in the shallower parts, for long timber was not obtainable. Consequently the ships which the crafty Cortes had caused to be built could sail along the causeway ahead of his troops who were attacking it, and could take the Mexicans in flank and in rear. No one could stand there against their shot. No wonder that the king of Mexico and Teotlili looked at Roger in dismay, and that the latter stood to his full height, looking back along the causeway with a frown on his sunburned face. "If they were in the ocean----" commenced Peter, shuffling from one leg to the other, for the presence of royalty always unsettled him, and he was beginning to have a huge respect for Roger. "The brigantines, you mean? But they are here, in the lake. What then?" "If they were at sea, I should try a plan to turn them out," said Peter, somewhat abashed. "They would fly if there was fire, and, master Roger, there might be fire here. We could float a canoe, one of the big ones, down upon them, and that would send them running."