Big John and Scotty had ridden on toward Papago Tanks with the buck on saddle after the kill. They had not waited for Sid, for it was their custom when any one went off lone hunting not to expect him back before nightfall. Blaze followed on after the white mustang’s tracks, sore and weary, his tongue hanging out with thirst and a high fever raging in him. Oh, to find Master! _He_ would know! He would get him a canteen or something! To drink and drink and drink! To have cool strong hands draw out this burning pain that seared his shoulders like a hot iron! Only the indomitable courage of his breed kept him up. Blaze was a thoroughbred. He did not know what a streak of cur blood was! Kootenai Firebrand, Culbertson Rex, Champion Swiveller, all famous lion dogs of the West, were among his forebears and they would not let him give up. He staggered on, his feet wabbling crazily under him as the trail wound on southward through a country of black lava cones all around him, with vitrified and scoriated lava under foot. Then Blaze stopped, for the horses had halted here. He looked wearily up toward a huge cone that rose to the east of him. Up that way these tracks led, and he must follow, too! He arrived at the top, at last, and then gave a feeble yelp of joy. Here Master had got down off his horse, and the smell of him was sweet in Blaze’s nostrils! Below him stretched out a vast amphitheater, the sandy floor of a deep crater that was half a mile across. Through a gap in the opposite side the desert vegetation had come marching in, species by species, saguarro, bisanga, choya, creosote bush, to spread out on that wide floor three hundred feet below and cover it with green dots of vegetation. Blaze looked down, his doggy heart sinking with misgivings, for no one was down there. Could he _ever_ muster up the strength to climb down into this thing? And where had Master come up out of it again? Only one set of tracks led down here and the descent was as steep as a chimney.