"Oh! my! three, you said, Frank; and that would mean Eugene, Spanish Joe, and Abajo, wouldn't it?" "Just the very ones I meant," replied Frank. "Then they must have been hiding some place near here, and saw the Moqui pass in?" suggested Bob, fully aroused by now. "That seems to be what happened," Frank observed. "But here comes Charley Moi with the guns. See how he dodges about, so as to keep hidden from the view of anybody up in those windows above, which we can't glimpse from here." When Bob eagerly took his repeating rifle from the hands of the Chinaman he exhibited all the evidence of great satisfaction; for he heaved a sigh of relief, and fondled his weapon in a way that caused his comrade to smile. "I feel better now," Bob confessed; "because, to tell the honest truth, when you broke the news so suddenly it nearly gave me heart failure, Frank, to think that if those rascals sprang out at us we would be next door to helpless. Now let 'em be careful how they play their little game. But what does it all mean, do you suppose, Frank?" "I can only make a guess, and that may be wide of the truth," the other admitted. "By some accident they managed to get on the track of the Moqui. Though Havasupai thought himself smart, he was no match for such a cunning rascal as Spanish Joe, who is said to be the best trailer along the Arizona border. And they followed him right here." "That was last evening, just when you and I stood there down by the river, looking through the glasses up at the windows of the rock houses above," remarked Bob. "Yes. Perhaps they didn't go up right then." Frank went on. "I admit that I can't just make out how long ago these tracks were made. A better trailer might, you see, Bob. If Old Hank Coombs were only here now I'd be glad to turn the whole business over to him, and play second fiddle." "But some time between dark and morning these three rascals went in here, and surprised the hermit of Echo Cave--is that it, Frank?" "It covers the case all right," came the reply. "Say, do you think they are up there yet?" asked the Kentucky lad, in an anxious tone. "I think they must be, Bob, because all the tracks point one way, showing that the three men never came back. If they left the cave it must have been by some other way." "No use asking why they would want to get in touch with Uncle Felix!" continued Bob, as if bent on finding out everything he could in connection with the case. "We know what their reason was," Frank made answer. "When Abajo, hanging about the window of our ranch house, heard what we had to say about the message that came floating down the Colorado in that bottle, and carried the wonderful news to his employer, Eugene Warringford, he set the game going that must end right here. He has come with the intention of making Professor Oswald turn over that option to him; and he'll do it unless something we can offer prevents."