The other made a low sound that somehow Bob seemed to interpret as meaning a negative to his question.
"Then prospectors—Lopez and his bunch?"
"Uh!" Frank replied; and then himself lowering his lips to the ear of Bob he went on: "What's the matter with Peg and his crowd? They might have got up here ahead of us. Quiet now!"
Bob did not attempt to say another word. He had new food for thought. Yes, to be sure, Peg and his two cowboy guides had had plenty of time to climb that far up the side of Thunder Mountain. If they had taken daylight for the task of course they avoided the danger of getting lost, such as had overtaken the saddle boys. And if the nerve of Spanish Joe and Nick Jennings continued to hold out, when strange things began to happen, the boastful tenderfoot from the East stood a chance of making a discovery.
As the two crept closer, on hands and knees, they could hear the murmur of voices grow louder, even though the speakers were evidently talking in low tones. While the experience was altogether new to Bob, he enjoyed it immensely. Why, after all, it was not so very hard to place his hands and knees in such fashion that he felt able to move along almost as silently as a snake might have done.
Now he was even able to locate the spot from which the murmur of voices came. Yes, and when he looked closer he saw a tiny spark that glowed regularly, just as a firefly might sparkle every ten seconds or so.
Bob solved that little mystery easily. Of course it was Spanish Joe, smoking one of the little cigarettes which he was so frequently rolling between his fingers.
To be sure, the odor of tobacco smoke mingled with that of burning wood. And if Spanish Joe, why not the other cowboy who was in bad repute among the ranches; yes, and Peg himself?
Bob began to wonder what the programme of his chum might be. Surely they would not take the chances of crawling up much closer now. If discovered they would run the risk of being fired upon; and besides, there was no necessity for such rashness.
Then Bob discovered that when the wind veered a little, as it seemed to be doing right along, he could actually catch what was being said.