"Climb, I tell you!" snapped Frank.
"Oh! all right, Frank, if you say so," and Bob started to obey.
Fortunately he was an agile lad, and a very fair climber, for the task which he had set himself was no ordinary one. But, by wriggling more or less, Bob managed to finally get a grip on the cedar. After that it was easy work; and having succeeded in reaching solid ground himself, he aided the almost exhausted Frank to draw back.
"Whew! that was some work, now, and all because I was so silly as to slip over the edge of that little hole!" remarked Bob, as though disgusted with himself.
"Look here," said his chum; "lean over carefully, while I drop this match down."
As he struck the match, and then cast it from him it went downward twenty, thirty, forty feet before it was extinguished.
"Ugh!" shuddered Bob, "why, it must be all of a thousand feet down to the bottom, Frank! It scares me just to think of the narrow escape I had."
"Well, I reckon it's all of one hundred feet," replied Frank; "and that's enough to settle a fellow. But let's lie back here, and get our breath a bit before going on up. The cave can't be far off now, if what Joe said is so."
Both of the boys were panting after their unusual exertion, and Bob was glad of a chance to rest for even a brief time. Besides, another burst of thunder was starting in, and he fancied that it was louder than any that had gone before; just as if they might be drawing closer to the place from whence all this clamor came.
The cave that Spanish Joe had found and entered—could it have anything to do with the mystery of the mountain? Frank seemed to think so, and was bent upon ascertaining the facts.