slipped around it. Here he faced a notch in the
cliff. At the apex he turned abruptly into a ragged vent that split the
ponderous wall clear to the top, showing a narrow streak of blue sky.

At the base this vent was dark, cool, and smelled of dry, musty dust.
It zigzagged so that he could not see ahead more than a few yards at a
time. He noticed tracks of wildcats and rabbits in the dusty floor. At
every turn he expected to come upon a huge cavern full of little square
stone houses, each with a small aperture like a staring dark eye. The
passage lightened and widened, and opened at the foot of a narrow,
steep, ascending chute.

Venters had a moment's notice of the rock, which was of the same
smoothness and hardness as the slope below, before his gaze went
irresistibly upward to the precipitous walls of this wide ladder of
granite. These were ruined walls of yellow sandstone, and so split and
splintered, so overhanging with great sections of balancing rim, so
impending with tremendous crumbling crags, that Venters caught his
breath sharply, and, appalled, he instinctively recoiled as if a step
upward might jar the ponderous cliffs from their foundation. Indeed, it
seemed that these ruined cliffs were but awaiting a breath of wind
to collapse and come tumbling down. Venters hesitated. It would be a
foolhardy man who risked his life under the leaning, waiting avalanches
of rock in that gigantic split. Yet how many years had they leaned there
without falling! At the bottom of the incline was an immense heap of
weathered sandstone all crumbling to dust, but there were no huge rocks
as large as houses, such as rested so lightly and frightfully above,
waiting patiently and inevitably to crash down. Slowly split from the
parent rock by the weathering process, and carved and sculptured by ages
of wind and rain, they waited their moment. Venters felt how foolish
it was for him to fear these broken walls; to fear that, after they had
endured for thousands of years, the moment of his passing should be the
one for them to slip. Yet he feared it.

"What a place to hide!" muttered Venters. "I'll climb--I'll see where
this thing goes. If only I can find water!"

With teeth tight shut he essayed the incline. And as he climbed he bent
his eyes downward. This, however, after a little grew impossible; he had
to look to obey his eager, curious mind. He raised his glance and saw
light between row on row of shafts and pinnacles and crags