ight
now?" asked Frank, his face filled with sudden animation.

"If you mean that we try and beat Peg Grant at his own game, and learn
what the secret of Thunder Mountain is, I say yes!" answered Bob,
steadily.

"Shake on that!" he exclaimed. "I'm just primed for something that's
out of the common run; and what could be finer than such a game? I saw
Billy Dixon in town; and we can send back word to father that we've
gone off for a big gallop; so he won't worry if we don't turn up for a
few days. Is it a go, Bob?"

"Count on me," replied the other. "I don't know how it is, Frank; but
it strikes me that I'd like to cut in on that boaster in this thing.
If we managed to find out what makes that fearful booming in the
mountain, and told about it before he got a chance to blow his horn,
he'd feel cheap, wouldn't he?"

"He sure would, now," Frank said. "And when you look at it, he just
the same as gave us the challenge direct, because he hinted that we
didn't have the nerve to attempt such a big thing as this. Bob, we'll
call it a go! Wonder what Peg will say when he runs across us out
there in that lonely place? Wow! I reckon he'll be some mad."

"Let him," remarked Bob, carelessly. "He has no claim on Thunder
Mountain; has he? And we want to call his bluff, if it was one. So
just make up your mind we're in for a new experience. It may pan out a
heap of fun for us. And it will be worth while if we can settle the
question that has been giving these superstitious cowmen the creeps all
these years."

"Then let's get through with our business, send word by Billy, though
not telling what we've got in the wind, and then pick up a few things
we might need on a trip like this. After that we can drop out of town,
and take our time heading for the mountain; because I think I'd like
Peg to get there first, so that he couldn't say we'd stolen his
thunder."

Half an hour later the saddle boys, having finished their business, and
sent the Circle ranch cowboy galloping homeward bearing the message to
Mr. Haywood, were moving slowly through the main street of the town,
heading toward a store where they could pick up a couple of blankets, a
simple cooking outfit, and some of the substantials in the way of
bacon, coffee and the like, when they came upon a scene that instantly
attracted their attention.

It was a terrified cry that reached their ears at first, and caused
both boys to pull in their horses. Glancing in