ow," Halliday answered. "The two chances I had I was too
scared to find out."

Ward felt a cold anger against this man growing in him. This man had
been entrusted with the task of surveying the atmospheric conditions of
this area--a vital, desperately necessary job--and he was dawdling
along, timidly hugging the cover of this fortress because of a stupid,
half-imaginary fear of the natives of the area. He felt his cheeks
growing hot.

"We can't stay cooped up here indefinitely," he said. "How about the
work we're supposed to be doing. Or does that bother you?"

* * * * *

Halliday looked at him queerly and then dropped his eyes. He fiddled
nervously with his glasses.

Ward suddenly found the gesture maddening.

"For Pete's sake!" he exploded. "Leave 'em on, or leave 'em off, one or
the other. That's apparently your only job here, taking those damn
glasses off and putting them back on again."

"I'm sorry," Halliday said quickly, apologetically. "It's just a habit I
guess. It's a little something to break the nervous tension of being
here all alone, thinking...."

His voice trailed off and his hand moved nervously toward his glasses
and then fell back limply in his lap.

"About the work here," he said in a mild, controlled voice, "we are
forced to work on a definitely limited schedule. I have field apparatus
located at points several miles distant from here. But we can't venture
out to take the necessary readings until the weather is propitious."

"What's the weather got to do with our taking readings?" Ward demanded.

"Simply this: There are certain periods of intense precipitation on this
area of Mars. These periods are accompanied by high velocity winds. The
atmospheric disturbance reaches monsoon proportions. During such
periods, for some reason, the Raspers are exceptionally active.
Something in the nature of the monsoon reacts on them with very savage
results. They seem to feed on the electric disturbances in the
atmosphere. They go wild during these changes in the weather and search
for any moving thing to destroy. In some manner they are able to cover
enormous distances during the monsoon and they can travel with
incredible speed. When a monsoon is threatening I never leave the
station."

Ward listened in growing irritation to this explanation.

"How often do you have monsoons here?" he demanded.

"Unfortunately, quite often," Halliday answered. "All of my instrument