"Y--yes, I reckon we would, after you'd prowled around a little, and had some chance to look the ground over. Then you believe he must have found the presence of those windows looking out of the cliff just like we did; by using a powerful glass? And, thinking that here was the very place for him to hide and study, he set about looking for the road up, and found it, very likely." "He did it by using common sense, and applying all he knew about the ways of these people of the long ago," replied Frank. "And you can see that if he chose, he could have thrown that bottle out of one of the openings up there, so that it would drop in the passing current of the Colorado, to be carried down-stream until somebody saw it; and finding the message to my father, sent or carried it to Circle Ranch." "Well," observed Bob, with a gleam in his eye, "now that we've found a way to get up to Echo Cave, have we the nerve to start in?" CHAPTER XIX FORTUNE STILL FAVORS THE BRAVE Instead of replying at once to this question, as Bob undoubtedly thought his chum would do, Frank seemed to give a start. He dropped to his hands and knees, and seemed to be examining some marks on the ground. If ever the fair knowledge of reading tracks which Frank possessed was called upon to do duty, it was now. Bob, of course, could not understand what possessed his comrade; but simply stood there and stared, wondering what Frank had found to cause him to exhibit such breathless interest, and all the signs of unusual excitement. When finally the lad on his knees did look up, Bob saw a grave expression on his face. "There's something wrong, Frank; tell me what it is?" he demanded. "I've made an unpleasant discovery, Bob," replied the other. "Charley!" he added turning to the wondering Celestial, "go back to our camp, and bring our guns right away, both of them, see?" "Yep, bloss, me unelstand. Charley Moi gettee gluns light away quick!" and as he said this the obliging Chinaman went on a run, his pigtail and blue blouse flying out behind him. "Say, whatever does all this mystery mean, Frank?" asked Bob, almost helplessly. "Just what you might imagine; that there's danger hanging about us, Bob." The eyes of the astonished Bob sought the ground at the point where his chum had been so deeply interested. "Then it must be something you just discovered there, and that's a fact," he declared; "because you didn't act this way three minutes ago." "I happened to discover footprints coming from another quarter," Frank went on, calmly; "and they headed into this crevice, just as those of the moccasined Moqui did from that side. And they came after old Havasupai had gone up, for I found where they wiped out a part of one of his tracks." "Footprints, and were they made by the old professor, do you think?" asked Bob. "Not any. Fact is," observed Frank, as though deciding to have the worst over, "they were the tracks of three persons, all men!"