e stallion leaped past him, barely missing
him. Out toward the plain the horse jumped, out and away from the shaded
canyon mouth, out toward the spot where other horses waited. And despite
the animal's blown condition, the speed he put into his retreat left
Kirby dazed.

* * * * *

After a helpless, profanity-filled second, Kirby scratched behind his
ear again. As certain as the fact that almost his sole hope of getting
back to civilization depended upon the stallion, was the fact that the
brute did not intend to stop running until he dropped.

"Now what in the hell ever got into his crazy head?" Kirby muttered
grimly.

Then he turned around to glance up the shadow-filled slash of a canyon,
and sniffed.

"Huh!"

Faintly in the air had risen an odor the like of which he had never
encountered in his life. A combination, it was, of the unforgetable
stench which hangs over a battlefield when the dead are long unburied,
and of a fragrance more rare, more heady, more poignantly sweet than any
essence ever concocted by Parisian perfumer.

With the drifting scent came a sound. Faint, carrying from a distance,
the rumble which Kirby heard was almost certainly that of a geyser.

There was no telling what had brought the troop of horsemen to a halt,
but after a time Kirby knew that the cause of his horse's sudden
departure must have been a whiff of the strange perfume.

* * * * *

For a long time he stood still, watching the crazy stallion dwindle in
size, watching the line of unexpectedly timid bandits. Then, when it
became apparent that the horsemen were going to stay put either until he
came out, or showed that he never was coming out, he shrugged, and swung
on his heel so that he faced up the canyon.

The odor was dying away now, and the geyser rumble was gone. In Kirby's
heart came a mingled feeling of tense uneasiness and fascinated
curiosity. Momentarily he was almost glad that his horse _had_ bolted,
and that his pursuers _were_ blocking any lane of retreat except that
offered by the canyon. If things had been different, the queer behavior
of the Mexicans, the unaccountable actions of his horse and the equally
strange growth of his own uneasiness might have made him uncertain
whether he would go up the canyon or not. Now it was the only thing to
do, and Kirby was glad because, fear or no fear, he wanted to go on.

"I wonder," he said out loud as h