a potential objective for examination.
Every broken hill might conceal some secret valley where subterranean
heat produced a growth foreign to the more open regions. He could afford
to miss no canyon however small, lest the secret he sought lay hidden
there. And all the time with the hot breath of the westerly breeze in
his nostrils, the lure of the sickly perfume beckoned him on.

* * * * *

It was sheer mental and bodily weariness that brought Steve to a
prolonged halt. The heat was overpowering him at last. This strange land
with its ruddy twilight had become a labour beyond endurance. It was as
if the waters of the river were being evaporated into a steam which left
the air unbreathable.

Halfway to the summit of a great wood-clad hill, that jettied across
from the southern slopes of the valley to the northern limits beyond, he
had flung himself to rest in a wide clearing surrounded by the cold
delicacy of white-hued foliage. In his moment of helplessness there
seemed to be no end to his journey. He felt that the great summit he
was reaching towards meant only a descent beyond, and then again
another, and still another steep ascent.

Only for a few moments had he sprawled, seeking rest. He was thinking
and gazing back over his long solitary trail, peering into the reverse
of that upon which he had looked so long. It was intensely restful thus
to turn his gaze from the belching fires. Once his heavy eyelids closed.
But he bestirred himself. Later he would sleep, but not now. His day's
work was--Again his eyes closed heavily, and his hand fell from the
support of his head.

It was that which wakened him. And in a moment a thrill of panic flashed
through his nerves. With all his will flung into the effort, he forced
himself to complete wakefulness. He sat up. He groped in his loosened
pack. He pulled out of it the mask he had tested once before, and, with
desperate haste, adjusted it over mouth and nostrils.

It had been near, so near. He knew now how nearly disaster had clutched
at him. Furthermore he knew that even now the danger was by no means
passed. The heavy fumes of Adresol were creeping through the woods about
him. They were stealing their ghostly, paralyzing way low down upon the
ground, drifting heavily along until the open below brought them to the
stronger air currents which would disperse them on their eastward
journey, robbing them of their deadly toxin, and reducing