air-current of the Erentz circulation. Like poison in a man's veins,
reaching his heart, the free alien electrons had disturbed the motors.
They accelerated, then retarded. Pulsed unevenly, and drew added power
from the reserve tanks. But they had normalized at once when the shot
was past. The duty-man's voice sounded from the grid in answer to
Grantline's question:

"Five degrees colder in your building. Can't you feel it?"

The disturbed, weakened Erentz circulation had allowed the outer cold
to radiate through a trifle. The walls had had a trifle extra
explosive pressure from the room-air. A strain--but that was all.

"It's probably their most powerful single weapon, Gregg." Grantline
said.

I nodded. "Yes. I think so."

I had smashed the real giant, with its ten-mile range. The ship was
only two miles from us, but it seemed as though this projector were
exerted to its distance limit. I had noticed on the deck only one of
this type. The others, paralyzing-rays and heat rays, were less
deadly.

Grantline commented: "We can withstand a lot of that bombardment. If
we stay inside--"

That ray, striking a man outside, would penetrate his Erentz suit
within a few seconds, we could not doubt. We had, however, no
intention of going out unless for dire necessity.

"Even so," said Grantline. "A hand-shield would hold it off for a
certain length of time."

* * * * *

We had an opportunity a moment later to test our insulated shields.
The bolt came again. It darted along the front face of the building,
caught our window and clung. The double window-shells were our weakest
points. The sheet of flashing Erentz current was transparent: we could
see through it as though it were glass. It moved faster, but was
thinner at the windows than in the walls. We feared the bombarding
electrons might cross it, penetrate the inner shell and, like a
lightning bolt, enter the room.

We dropped the curtain corner. The radiance of the bolt was dimly
visible. A few seconds, then it vanished again, and behind the shield
we had not felt a tingle.

"Harmless!"

But our power had been drained nearly an aeron, to neutralize the
shock to the Erentz current. Grantline said:

"If they kept that up, it would be a question of whose power supply
would last longest. And it would not be ours.... You saw our lights
fade down while the bolt was striking?"

But the brigands did not know we were short of power.