ed,' can be hardened to the point
of disruption. It can be shattered, Tema, by vibration! That's why the
space ship keeps far above the roar of cities! The humming of countless
automobile engines might shatter the rind! God, I hope this is the
answer!"

In his mind's eye Eyer could picture it--the outer rind "freezing"
solid, and cracking with the thunderous report of snapping ice on a
forest lake. No wonder Sitsumi and the Three must destroy the six
planes.

"Now!" yelled Sitsumi. "Shift positions! The space ship will be hurled
directly at the formation of planes! Wang Li, to the beam controls!"

Wang Li sprang to the table, pressed a button. The humming sound in the
space ship grew to mighty proportions. The trembling increased.

Jeter and Eyer kept their eyes glued to the six planes above. Without
tilting their noses the six planes seemed to plunge straight down toward
the surface of the space ship. Thus the two knew that the space ship was
in motion--itself being bodily hurled, as its only present weapon of
offense, against the earthling attackers.

A split second--

One of the planes struck the surface solidly and crashed. Instantly its
wheels and its motor were caught in the outer rind.

The other five ships scattered wildly, escaping the collision by some
sixth sense, or through pure chance.

"Poor devil!" said Jeter. "But his buddies can see his plane and know
that it marks the spot where they could conveniently drop their bombs."

Eyer was on the point of nodding when Sitsumi shouted.

"Quickly, Wang Li! Spin the outer shell before the enemy uses the
wrecked plane as an aiming point!"

* * * * *

A whirring sound. The plane whirled around as though it were twirled on
the end of a string. To the five other pilots it must have seemed that
the plane had struck some invisible obstruction, been smashed, and now
was whirling away to destruction after a strange, incomprehensible
hesitation in the heart of the stratosphere.

"Quickly, you fool!" shouted Sitsumi at Wang Li. "You're napping! You
should have got all those planes! And you should have spun the outer
globe instantly, before the remaining enemy had a chance to find out our
location."

"I can move away a half mile," suggested Wang Li.

"We've got to silence those motors, fool!" yelled Sitsumi. "You know
very well that we can't run. Charge them again, and take care this time
that you crash into the middle of the