d the thunder
from the stern was deafening despite their insulated walls. The
shuddering structure beneath them was hurled forward till the needle
of the speed-indicator jammed tightly against its farthest pin. And
ahead of them was no emptiness of space.

* * * * *

The air was alive with darting forms. Harkness saw them plainly
now--great trailing streamers of speed that shot downward from the
heights. The sun caught them in their flight to make iridescent
rainbow hues that would have been beautiful but for the hideous heads,
the sucker-discs that lined the bodies and the one great disc that
cupped on the end of each thrusting snout.

And beneath those that fell from on high was a cluster of the same
sinister, writhing shapes which clung to a speeding ship that rolled
and swung vainly in an effort to shake them off.

The coiling, slashing serpent-forms had fastened to the doomed ship.
Their thrashing bodies streamed out behind it. They made a cluster of
flashing color whose center point was a tiny airship, a speedster, a
gay little craft. And her sides shone red as blood--red as they had
shone on the grassy lawn of an old chateau near far-off Vienna.

"It's Diane!" Harkness was shouting. "Good Lord, Chet, it's Diane!"

This girl he had told himself he would forget. She was there in that
ship, her hands were wrenching at the controls in a fight that was
hopeless. He saw her so plainly--a pitiful, helpless figure, fighting
vainly against this nightmare attack.

Only an instant of blurred wonderment at her presence up there--then a
frenzy possessed him. He must save her! He leaped to the side of the
crouching pilot, but his outstretched hands that clutched at the
control stopped motionless in air.

* * * * *

Chet Bullard, master-pilot of the first rank, upon whose chest was the
triple star that gave him authority to command all the air-levels of
earth, was tense and crouching. His eyes were sighting along an
instrument of his own devising as if he were aiming some super-gun of
a great air cruiser.

But he was riding the projectile itself and guiding it as he rode. He
threw the ship like a giant shell in a screaming, sweeping arc upon
the red craft that drove across their bow.

They were crashing upon it; the red speedster swelled instantly before
their eyes. Harkness winced involuntarily from the crash that never
came.

Chet must have missed i