rose and walked
beside him. For not alone these ribs of gleaming limestone contributed
towards the elemental visages, but the entire hills, of which they were
an outcrop, ran to assist in the formation, and were a necessary part of
them. He was watched and stared at from behind, in front, on either
side, and even from below. The sand that swept him on, kept even pace
with him. It turned luminous too, with a patchwork of glimmering effect
that was indescribably weird; lanterns glowed within its substance, and
by their light he stumbled on, glad of the Arab boy he would presently
meet at the appointed place.

The last torch of the sunset had flickered out, melting into the
wilderness, when, suddenly opening at his feet, gaped the deep, wide
gully known as Wadi Hof. Its curve swept past him.

This first impression came upon him with a certain violence: that the
desolate valley rushed. He saw but a section of its curve and sweep, but
through its entire length of several miles the Wadi fled away. The moon
whitened it like snow, piling black shadows very close against the
cliffs. In the flood of moonlight it went rushing past. It was emptying
itself.

For a moment the stream of movement seemed to pause and look up into his
face, then instantly went on again upon its swift career. It was like
the procession of a river to the sea. The valley emptied itself to make
way for what was coming. The approach, moreover, had already begun.

Conscious that he was trembling, he stood and gazed into the depths,
seeking to steady his mind by the repetition of the little formula he
had used before. He said it half aloud. But, while he did so, his heart
whispered quite other things. Thoughts the woman and the man had sown
rose up in a flock and fell upon him like a storm of sand. Their impetus
drove off all support of ordinary ideas. They shook him where he stood,
staring down into this river of strange invisible movement that was
hundreds of feet in depth and a quarter of a mile across.

He sought to realise himself as he actually was to-day--mere visitor to
Helouan, tempted into this wild adventure with two strangers. But in
vain. That seemed a dream, unreal, a transient detail picked out from
the enormous Past that now engulfed him, heart and mind and soul. _This_
was the reality.

The shapes and faces that the hills of sand built round him were the
play of excited fancy only. By sheer force he pinned his thought against
this fact: