t a horse carrying two men
cannot run away from a horse carrying one man, but they also knew the
country, and this knowledge taught them that if they could reach the
narrow passage through the old clay bluff, they might be able to escape
to Peterson's, which was situated a number of miles beyond. This would
be possible, because men climb faster when danger is behind them than
when it is in front. Besides, a brisk defence could render even an angry
Mexican a little doubtful as to just when he should begin to climb.
Accordingly, Alfred urged the pony across the flat plain of the ancient
riverbed toward the nearest and only break in the cliff. Fifteen miles
below was the regular passage. Otherwise the upper mesa was as
impregnable as an ancient fortress. The Mexicans had by this time
succeeded in roping some of the scattered animals, and were streaming
over the brow of the hill, shouting wildly. Alfred looked back and
grinned. Tom waved his wide sombrero mockingly.

When they approached the ravine, they found the sides almost
perpendicular and nearly bare. Its bed was V-shaped, and so cut up with
miniature gullies, fantastic turrets and spires, and so undermined by
former rains as to be almost impassable. It sloped gently at first, but
afterward more rapidly, and near the top was straight up and down for
two feet or more. As the men reached it, they threw themselves from the
horse and commenced to scramble up, leading the animal by the
bridle-rein. From riding against the sunset their eyes were dazzled, so
this was not easy. The horse followed gingerly, his nose close to the
ground.

It is well known that quick, short rains followed by a burning sun tend
to undermine the clay surface of the ground and to leave it with a hard
upper shell, beneath which are cavities of various depths. Alfred and
Tom, as experienced men, should have foreseen this, but they did not.
Soon after entering the ravine the horse broke through into one of the
underground cavities and fell heavily on his side. When he had scrambled
somehow to his feet, he stood feebly panting, his nostrils expanded.

"How is it, Tom?" called Alfred, who was ahead.

"Shoulder out," said Tom, briefly.

Alfred turned back without another word, and putting the muzzle of his
pistol against the pony's forehead just above the line of the eyes he
pulled the trigger. With the body the two men improvised a breastwork
across a little hummock. Just as they dropped behind it