den out of it; but the
moon was under thick clouds, and the gloom of the ravine was no longer
relieved by her light.

"It would be their trick," reflected he, "to get inside the canon, at
its narrow part, and wait for me to come out of the cave. They would
waylay me pretty handy there. Now suppose they _are_ up the canon at
this moment!"

For a moment he paused and dwelt upon this hypothesis. He proceeded
again.

"Well, let them; I'll ride on. Cibolo can beat the rocks a shot's range
ahead of me. If they're ambushed there without him finding them,
they'll be sharper fellows than I take them to be; and I don't consider
them flats, either, the scoundrels! If he start them, I can soon gallop
back out of their reach. Here! Cibolo!"

The dog, that had stopped a few paces in front, now came running back,
and looked up in his master's face. The latter gave him a sign,
uttering the simple word "Anda!"

At the word the animal sprang off, and commenced quartering the ground
for a couple of hundred yards in advance.

Following him, the horseman moved forward.

In this way he approached the point where the two walls converging
narrowed the canon to a space of little more than a hundred yards.
Along the bases of the cliffs, on both sides, lay large loose rocks,
that would have given cover to men in ambush, and even horses might have
been concealed behind them.

"This," thought Carlos, "would be the place chosen for their cowardly
attack. They might hit me from either side with half an aim. But
Cibolo makes no sign.--Ha!"

The last exclamation was uttered in a short sharp tone. It had been
called forth by a low yelp from the dog. The animal had struck the
trail where the yellow hunter and his companion had crossed to the
middle of the ravine. The moon had again emerged from the clouds, and
Carlos could see the dog dashing swiftly along the pebbles and up the
ravine towards the mouth of the cavern!

His master would have called him back, for he was leaving the loose
rocks unsearched, and, without that being done, Carlos felt that it
would be perilous to proceed farther; but the swiftness with which the
dog had gone forward showed that he was on a fresh trail; and it now
occurred to the cibolero that his enemies might be within the cave
itself!

The thought had hardly crossed his mind when the dog uttered several
successive yelps! Although he had got out of sight, his master knew
that he was at that momen