A great sob rose in Sid’s throat as what all this meant came over him in an overwhelming wave of emotion. What Scotty _might_ have done in leading here the slow advance of civilization, that villain Vasquez had brought about in one mad moment of callous cupidity. Sid ground his teeth in helpless rage. Then he turned and raced for Scotty’s bunk up near the mine. He, the engineer--he could stop this catastrophe if any one could! Already, as he passed, he could see the bottom of the tank, dim and muddy below the fast vanishing level of the water. Around its edges Apache women were wailing and wringing their hands, some drawing water while any yet remained. Honanta and his braves had gathered and stood looking down at the tank in stolid perplexity, helpless, knowing not how or why this cruel thing was happening, nor what to do. “Wake, Scotty! Quick! Our water’s all going from the tank! Help us, old man--hurry!” shouted Sid wildly, shaking him. Scotty sat up, and immediately his eyes fell on water level, now far down in the lava basin, the pool itself shrunk to half its normal size. “That explosion must have cracked a fissure open somewhere, last night,” said Sid. “Only look, Les!” he groaned. Scotty pulled on his boots rapidly. “No use trying to stop it from below, Sid,” he declared with the sure knowledge of the engineer. “The water head would burst any dam we could build down there. We’ve got to find the crack in the bottom up here and stop it. All hands into the tank!” he cried energetically. Sid waved his arm to Honanta and his bucks to jump in and join in the search for the leak, but they stood back, arms folded, eying him gloomily. Childlike, in many ways, is the Indian mind! Before anything whose cause they cannot reason out they stand helpless. Only Niltci followed Sid and Scotty into the water, and that from blind obedience. “Hunt for a hole in the tank bottom, Niltci!--Hunt for all your worth!” ordered Sid, handing him a stick as they waded about the pool. Its water was now less than three feet deep, the bottom smooth and slippery with mud. Somewhere down there a crevice, maybe only an inch wide, was drawing down the water--but where! The bottom was smooth and hard as flint; nowhere did the searching sticks find any crack that had no bottom. Scotty’s face grew more and more concerned as they reached the end of the tank away from the lava outflow. Here it grew deeper and the bottom was all ragged pot holes of scoriated lava. Here gases had forced their way out from below while yet the molten stuff was soft. His stick felt down into deep jagged holes and could tell him nothing as to whether a fissure existed at the bottom of them or not.