filling the valley with their sweet silver clamour; but as the boys
approached and skirted the wall, some distance to the right, the Mission
might have been as lifeless as it is this year, in its desertion and
decay.

The hills were a mile behind. The Mission, like all of its kind, stood
on a broad open, that no hostile tribe might approach unseen. Cows and
horses lay in their first heavy sleep, their breathing hardly ruffling
the profound stillness. So great an air of repose did the silent walls
and sleeping beasts give to the landscape that the boys felt the quiet
of the night as they had not done in the other valley, and drew closer
together, almost holding their breath lest the priests might hear it. A
quarter of an hour later they were among the hills and standing before
the aperture whose secrets were known only to Padre Osuna. They glanced
at each other out of the corners of their eyes. Brave as they were, they
did not altogether like the idea of a possible encounter with a
rattlesnake or a bear in the dark and narrow confines of a cave. And if
there should be another earthquake! However, they had not come to turn
back, and Roldan pushed boldly in, the others following close.

For a time their way lay along a narrow passage. They had made two
abrupt turns before they dared to light the lantern they had brought.
When Rafael did, it revealed nothing but earthy walls and the imprint of
feet on the ground. After a little, however, the passage suddenly
widened, and it was Adan who uttered the first exclamation of surprise.
It was, indeed, a hoarse gurgle. The walls were veined with what
appeared to be irregular bands of dirty crystal, pricked with glittering
yellow. There were, perhaps, a thousand of these little points bared
from the jealous earth, and they shone with a steady baleful glare,
magnetising six youthful eyes, stirring in three careless brains the