As the last words of this dismal chant rang out, an echo seemed to
be flung back at the singer from behind a neighboring ridge, upon
which the lone yuccas stood upright, like, so many figures of formed
bits of humanity.

"Ye-e-e-e-e-e-e!"

It came in a long drawn out wail that fairly seemed to make the
desert ring with its gruesome echoes. All at once it was taken up
from another point. Then another echoed it back. It seemed to be
proceeding from a dozen quarters of the compass at once.

Strong nerved as all three of the riders were, it appeared to make a
strange impression on them.

"What in the name of Kit Carson wuz that?" demanded Red Bill drawing
rein.

"Dunno. It sounded like someone havin' fun with that ther cheerful
little song of yourn," said the black-mustached man.

"That's what it did. I'd like to find the varmint. I'd make some
fun fer him."

The man scowled savagely. His nerves had been unpleasantly shaken
by the wild, unearthly cries.

"It didn't sound human," he said at length; "tell you what, let's
jes' look aroun' and see if we kin find any trace of who done it."