gh his body, sharpening his reflexes and
alerting his muscles for action.

He never ceased to wonder about this faculty he had acquired for
sensing the presence of danger. There was no doubt in his mind that it
had come into active function through the influence of his
environment. But it must have been an intrinsic part of him even
before that, waiting to be activated.

A moment before he had localized the source of his uneasiness--an
Earthman, following perhaps fifty paces behind him. The one quick
glance Johnson had allowed himself told him his follower was above
average in height, and lean--with the wiry, muscular command of
himself that marked him as a man capable of well-coordinated action.

He fought the rising force of the next "sand-blaster" boiling in from
the desert, until he was unable to take a step against it. Then he
moved behind a mud-packed arm projecting from the native dwelling at
his right. Every building had one of these protecting arms added on;
even the concrete buildings in the newer, Earth-built section of the
city conformed to the custom. The sandstorms raged intermittently on
Marlock through the entire nine month summer season, and could not be
ignored, either by visitors or natives.

Johnson huddled against the projection, but the sand whipped around
the corner and pounded at his back. Fine grains sifted through his
clothing and mingled with the clammy sweat of his body. He resisted
the frantic urge to scratch his itching, tormented skin, for he knew
the flesh would be rubbed raw in a minute and increase the irritation
to maddening proportions.

As the "sand-blaster" lost its intensity, he came out from his shelter
and walked away as rapidly as the diminishing force of the wind would
permit. If he could reach his office before his stalker closed in, he
would be safe.

Suddenly a second Earthman, a short length of pipe in his right hand,
came out of a doorway across the street and ran toward him.

Johnson realized that here was the source of the warning his intuition
had sent--not the man behind him.

* * * * *

For a brief instant, he weighed the situation. The man was equipped
for assault, but the chances were he was interested only in robbery.
Johnson could probably save himself a beating by surrendering his
money without resistance. He rejected the thought. A man had to live
with his pride, and his self-respect; they were more necessary than
physi