you're joshing me, Frank!" declared the Kentucky lad, reprovingly.

"I am not," replied the other, immediately. "Suppose there was any
truth in that fairy story about the fires away down in the earth here;
don't you think a fellow might get a whiff of the brimstone if he was
Johnny on the spot? Why, honest now, Bob, it was on my mind to find
some sort of cave up here, and go in just as far as we could. Don't
you see the point?"

"Oh! I reckon I do, Frank. You take little stock in that yarn; but,
all the same, you think we ought to look into it, now we're on the
ground?"

"That's it, Bob. Why, even my dad kind of favors that idea, and I want
to either prove it a fake, or learn that there's something to it."

So they lay there, lazily enough, instead of climbing farther up the
side of the mountain. It was very pleasant to keep in the cool shade
of the trees, with that trickling little stream so near, for, as the
afternoon advanced, it seemed as though the air became very oppressive.

Frank was looking up at the sky many times, and finally his companion
asked him what was on his mind.

"I don't pretend to be a weather sharp," Frank replied; "but, all the
same, there are signs up there that've got me guessing."

"Well, it _is_ clouding up some," replied Bob, as he swept a look
around at what they could see of the arch overhead. "Perhaps the long
drought is going to be broken at last, Frank. Your father will be
tickled, if it turns out that way. He's been complaining of late about
the stock having to hunt twice as far away from the ranch for forage.
A rain would make things green again."

"Sure it would," replied Frank; "but, as I said to you before, a rain
storm up in the Rockies is sometimes no joke. We may have to do some
tall climbing if it gets a whack at us when we're in the canyon."

The day was passing. They had seen nothing more of Peg Grant and his
two guides, but could easily believe the others were not a great way
off. Perhaps they, too, were only waiting for night to come in order
to start their investigation.

"I don't think either Spanish Joe, or Nick, could be depended on, if
the thing began to look too spooky," Frank had said more than once,
showing that his thoughts must be running in the direction of the rival
party.

"Oh! this is easy," chuckled Bob. "If all we've got to do is to squat
here and take notes when the menagerie begins to wake up, it's going to
be a snap."

Frank