"How can men be such ruffians?" wondered Jack to himself, as he heard. He knew now why he had instinctively mistrusted Harding from the first. Yet they had saved his life that very morning. Was Harding going to return evil for good, by betraying them to their merciless enemies? It looked so. The former West Pointer's feet were close to the cave mouth now. Crouching back in the dark, the lads awaited what the seconds would bring forth. Jack's active brain, in the brief time he had had for revolving plans to avert the catastrophe that seemed impending, had been unable to hit upon one hitherto. Suddenly, however, he gave a sharp exclamation, and muttered to himself: "I'll do it. It can do no harm, anyway." "Well, is it a cave?" The question came up from below, in Ramon's voice. The ruffian's accents fairly trembled with eagerness. "Don't know yet--this confounded brush. What!" Harding, who had crawled in among the chapparal, started back, as Jack's voice addressed him, coming in low, tense accents from the interior of the cave: "Remember, Harding, we saved your life this morning--are you going to betray us now?" "Is that you, Merrill? You see I know your name. That was a shabby trick you worked on us." "Shabby trick! Our lives were at stake," retorted Jack. "Hurry up thar, young feller," came from below in Rafter's voice; "by hemlock, I thought I hearn horses up ther canyon apiece." "All right; I'll be there--just investigating," flung back Harding. "What do you want me to do, Merrill?" "What your own conscience suggests," was the reply. "But, if they ever found out, it would cost me my life," almost whimpered Harding, all his craven nature showing now. "But they never will. Don't let them know we are here, and ride on. We will escape, if possible, and if we are caught, your secret is safe with us." "You--you'll promise it?" "On my honor." "I'll--I'll do it, then, Merrill; but for Heaven's sake, don't betray me." "You need not fear that," rejoined Jack, with a touch of scorn in his voice. "I have given my word." "Say, young feller, hev yer found a gold mine up thar?" shouted Rafter. "What is detaining you, Senor Harding," came Madero's voice. "Nothing, sir," rejoined Harding, diving out of the bushes once more, and standing erect on the hillside; "that cave was quite deep, and it took me some time to make sure it was empty." "Empty! By chowder, them _wuz_ horses, I hearn up ther canyon, then," ejaculated the lanky Rafter. "You found no traces of those lads there, senor?" It was Ramon who spoke now, all his sinister character showing in his face. "Not a trace of them," rejoined Harding, scrambling down the hill, grasping at bushes, as he half slid on his way, to steady himself.