he floor of the cave,--after
having tied the horse to a bowlder just outside. He was a fine animal,
black as jet and as high-spirited as Spitfire himself. Ted appraised him
with longing eyes, for he loved horses as Ace loved his ship. But who
could he belong to, and how did he come to be there?

His bridle was embellished with silver. "Mexican handiwork, that!" Pedro
thought. But the mystery was no nearer solution.

The answer came sooner than they expected.

CHAPTER VI

THE INCENDIARIES

The red glow of the sun on the snow-clad peaks of the main ridge had
begun glinting through the smoke gloom when voices seemed to echo from
within the very rock against which they were leaning. The boys crept to
look behind it. Then their eyes rounded in astonishment. As Ted would
have spoken, Pedro clapped his hand over his mouth with a look that bade
silence. Crouched motionless at the side of the cave mouth,--for a deep
cave it now disclosed itself,--the two boys peered at the spectacle that
greeted their eyes.

Three Mexicans, aglitter with the silver buttons of their native costume,
appeared suddenly from some black depth, carrying torches.

With these one of their number kindled a bon-fire, whose flame revealed a
couple of burros standing patiently under their packs, tied to a mammoth
stalagmite. For the red flare behind the three figures of the Mexicans,
showed a cave roofed with amber-tinted icicles of smoke-stained rock,
beneath which up-rose for each a pyramid of the same formation.

The Mexicans might have been father and son and old servant, from their
general appearance and from the fact that most of the work of
supper-getting was performed by the shabby, white-haired one, while the
fat middle-aged one struck the younger a blow that was not reciprocated.
They were talking in a tongue that Ted could not translate, though from
the peppery tone of it, he judged they were quarreling. Pedro assured him
later they were not. (He knew Mexican.) They were merely regretting that
their horse had been burned.

The fat one, evidently too fagged to move, was demanding that one of the
others go see for sure, while they argued that it was no use, the animal
could not have survived. They must have been exhausted, lame, besides, to
judge from the creaky way they moved. The fat one poured some verbal
vitriol on their heads for not having brought the horse inside, while the
white haired one deprecated that they had not inten