ack, and such a thought
crossed his mind, but was gone in an instant. He had come to take the
man's life, but not in that manner. Even prudence suggested a better
plan. His knife would be more silent, and afford him a safer chance of
escape when the deed was done! With this idea, he brought the butt of
his rifle gently to the ground, and rested its barrel against the
parapet. The iron coming in contact with the stone wall gave a tiny
clink. Slight as it was, it reached the ear of the Comandante, who
wheeled suddenly round, and started at the sight of the intruder.

At first he exhibited anger, but the countenance of the cibolero, that
had undergone a complete metamorphosis during the short interval, soon
changed his anger into alarm.

"How dare you intrude, sir?--how dare--"

"Not so loud, colonel!--not so loud--you will be heard!"

The low husky voice, and the firm tone of command, in which they were
uttered, terrified the cowardly wretch to whom these words were
addressed. He saw that the man who stood before him bore in his face
and attitude the expression of desperate and irresistible resolve, that
plainly said, "Disobey, and you are a dead man!" This expression was
heightened by the gleaming blade of a long knife, whose haft was firmly
grasped by the hand of the cibolero.

At sight of those demonstrations, Vizcarra turned white with terror. He
now comprehended what was meant. The asking for the troop had been but
a subterfuge to get near his own person! The cibolero had tracked him;
his guilt was known, and the brother was now come to demand redress or
have vengeance! The horrors of his night-dream returned, now mingling
with the horrors of the fearful reality before him.

He scarce knew what to say--he could scarce speak. He looked wildly
around in hopes of seeing some help. Not a face or form was in sight--
nothing but the grey walls, and before him the frowning face of his
terrible antagonist. He would have called for help; but that face--that
angry attitude--told him that the shout would be his last. He gasped
out at length--

"What want you?"

"_I want my sister_!"

"Your sister?"

"My sister!"

"Carlos--I know not--she is not here--I--"

"Liar! she is within these walls. See! yonder the dog howls by the
door. Why is that?"

Carlos pointed to a door in the lower part of the building, where the
dog Cibolo was at that moment seen, whining and making other
demonstrations, as if