the highest efficiency
of electro-chemical conversion, in practical form, in the lead acid
storage battery.

After finding the light switch and flipping it on, Aron found this lever
and released it. Now all he needed was wind, and he had that, blowing a
cool ten miles an hour down the canyon and over the valley. He had to
consult the weather maps at his station for weeks to determine the
probability of this wind occurring and the weather conditions that
produced it. One small breeze to chart, when his recording instruments
gave hourly descriptions of the whole planet's climate. It wasn't too
hard a job.

Yet that breeze had to be at the right time, at night and on the night
he wanted. Close enough to the attack date to be effective yet not too
soon. Last night his instruments recorded the data that would produce
this wind, so he was making his strike tonight.

He could not stand and gloat exultantly over his success. There were
dead sentries and sprung airlocks that might be discovered.

With a twist of a nozzle, the fire hose came to life, throwing a pulsing
stream of water on the batteries.

What Aron had done by ingenuity, luck, daring and careful planning was
finished. It was now nature's turn.

* * * * *

The next night after his one man attack on the base, Aron had a visitor
at his weather station. The visitor was in sad shape. His clothing was
disheveled, his face dirty and unshaven, his eyes bloodshot and he
seemed to be on the verge of a mental collapse with a frantic gleam to
his eye.

But he held a pistol in his hand and Aron didn't.

He was an officer of the Intelligence Corps of the People's Republic. It
was not the officer who had first visited Aron, but one of the others
that Aron had come vaguely to know, like picking out sheep from a flock.

He had been away from the base on a planetary reconnaissance mission the
night before. Since then he had gone through a nightmare ordeal.

He had returned to his base to find sixty ships of the People's Republic
about to fall into enemy hands without a struggle, because 200,000 men
were dead or dying of chlorine gas poisoning.

The gas that had come pouring out of the warehouse at the head of the
valley last night. It had billowed down the valley, its streamers and
tentacles pushed by the gentle wind bringing the sleeping men awake
coughing and gasping only to fall asleep again--permanently.

It had seeped through the