e
that is riderless, and the prairie-man is rarely puzzled to distinguish
them. My companion at once pronounced the horses to be "mounted."

The guerrilleros, on the alert, had heard them at the same time as we,
and two of them had galloped out to reconnoitre. This we ascertained
only by _hearing_, for we could not distinguish an object six feet from
our faces--the darkness being almost palpable to the touch.

The sounds came from a considerable distance, but as they were
continually growing more distinct we could tell that the horsemen were
advancing _toward_ the mesa.

We drew no hope from this advent. Rube could not yet have even reached
the rancheria. The new-comers were El Zorro and his companion on their
return.

We were not kept long in doubt: the horsemen approached, and shouts and
salutations were exchanged between them and the guerrilleros, while the
horses of both parties neighed in response, as if they knew each other.

At this moment the lightning shone again, and to our surprise we
perceived not only El Zorro, but a reinforcement of full thirty men!
The trampling of many hoofs had half prepared us for this discovery.

It was not without feelings of alarm that we beheld this accession to
the enemy's strength. Surely they would no longer hesitate to assail
our fortress behind the rock? At least then our horses would be
captured? Besides, Rube's rescue might be too weak for such a force?
There were now nearly fifty of the guerrilleros.

Our anxiety as to the first two points was soon at an end. To our
astonishment, we perceived that no assault was to be made as yet. We
saw them increase the strength of their cordon of sentries, and make
other dispositions to carry on the siege.

Evidently they regarded us as hunters do the grizzly bear, the lion, or
tiger--not to be attacked in our lair. They dreaded the havoc which
they well knew would be made by our rifles and revolvers; and they
determined to reduce us by starvation. On no other principle could we
account for the cowardly continence of their revenge.

CHAPTER FORTY ONE.

THE INDIAN SPY.

It was past the hour of midnight. The lightning, that for some time had
appeared only at long intervals, now ceased altogether. Its fitful
glare gave place to a softer, steadier light, for the moon had arisen,
and was climbing up the eastern sky. Cumulus clouds still hung in the
heavens, slowly floating across the canopy; but their masses wer