time they
fancied they could see a dark form crouching along the ground in the
direction of the _mulada_, that was picketed not a hundred yards off.
The light, however, was so uncertain, not one of the five could be sure
of this. Whatever it was, it moved very slowly, for it appeared to
remain near the same spot.

Carlos at length set himself to observe it more closely. He stole out
from the corral, and, followed by Antonio, crawled along the ground.
When the two had got nearer the dark object, it was distinctly seen to
move.

"There _is_ something!" whispered the cibolero.

At that moment the mules again snorted, and one or two of them struck
the ground with their hoofs, as if startled.

"It must be a bear, I fancy," continued Carlos. "It has the appearance
of one. It will stampede the animals--a shot will be less likely to do
so."

As he said this he raised his rifle, and, taking aim as well as the
darkness would allow him, pulled trigger and fired.

It seemed as if the shot had invoked all the demons of the infernal
regions. A hundred voices burst forth in one simultaneous yell, the
hoofs of a hundred horses rang upon the turf, the _mulada_ got into
motion, the mules squealing and plunging violently, and the next moment
every one of them had broken their lariats, and were running at a
furious gallop out of the valley! A dark band of yelling horsemen was
seen closing in after and driving them off; and, before Carlos could
recover from his surprise, both mules and Indians had disappeared out of
sight and hearing!

Not a single one remained of the whole _mulada_. The ground upon which
they had been picketed was swept perfectly clear!

"An estampeda!" said the cibolero, in a husky voice; "my poor mules--all
gone--_every_ one of them! A curse upon Indian duplicity!"

Carlos had not the slightest doubt but that the marauders were the
Wacoes--the very same from whom he had purchased the mules. He knew
that such an occurrence was by no means rare--that oftentimes the
traders are robbed in this way; and not unusual is it for them to
purchase a second time the very animals thus carried off, and from the
same Indians who have stolen them!

"A curse upon Indian duplicity!" he repeated with indignant emphasis.
"No wonder they were so free and generous in their barter! It was but a
plot on the part of the cowardly thieves to take from me my whole cargo,
without daring to do so openly. _Carajo_! I am lost!