The latter had stopped; he stared for a few seconds at the man on the white wall above and finally signaled with a wave of his arm. "Come down here," he ordered. But Weir made no move to obey. He continued to stand motionless, coolly regarding the party beneath. His eyes particularly considered two men who carried wooden boxes, square and stout, on their shoulders. At last he spoke. "What do you want here?" "Come down, then you'll learn," Burkhardt shouted up, making no effort to hide the enmity in his voice. Weir puffed at his cigar, removed it from his lips to glance at its glowing end, while the Mexicans stared up at him in silence, puzzled by this lone guard who carried no rifle, who did not flee away to spread an alarm and seek aid, and who so unexpectedly had appeared as if anticipating their visit. Murmurs broke out. Why were they not allowed to shoot him at once in the approved Mexican bandit fashion and proceed to their work? If he were not shot at once, he yet could escape for aid. The party had to ascend the hillside in order to mount to the top of the concrete work. Time would be required to place and fire their charges of dynamite--and they were eager to get at the loot in the buildings above. "Kill him," Burkhardt roared suddenly, jerking forth his revolver and blazing at the engineer. The bullet sang past Weir's head. He did not duck; indeed, kept his place calmly while the Mexicans were raising their guns, as if to show his supreme contempt for their power. But at the instant Burkhardt fired again and a dozen rifles blazed he sprang back and dropped flat, leaving the deadly missiles to speed harmlessly above the dam. Raising himself cautiously he seized the end of a fuse projecting from one of the canisters and held the crimson end of his cigar against it until a sputter of sparks showed that it had caught. From this fuse he turned to the one in the second can and repeated the operation. This was the essence of his plan of defense. With guns the defenders on the hillside would be outnumbered and probably killed in an attack. The information that the assailants were to steal up the canyon, however, was the key that would unlock a desperate situation, and his mind had grasped the mode and means of defeating the enemy. With the first shots quiet had returned. The night seemed for Weir as peaceful as ever, the earth bathed in moonlight, the camp at rest. Only before him there was the sputter of the two fuses, one at the right, one at the left, as the trains of fire burned towards the holes in the canisters. He watched these calculatingly. His cigar no longer of service had been cast aside. All at once he rose erect again. A few men were starting along the wall to climb the hillside, but the greater number were gathered about Burkhardt and the Mexican leader. Now Weir glanced at them and now at the fuses.