nder staff upon whose tip they whirled vanished, shorn
short off above the vane-grooves in the top of the wing!

The plane dropped away, fluttering like a falling leaf for a moment,
before the aviator started his three propellers again.

A cheer broke from the lips of Prester Kleig as he watched. The
commander of that particular aero-sub, apparently contemptuous of this
flyer who had tried to cut out of the fight, allowed him to fall away
unmolested--and the American, driven berserk by the casual, contemptuous
treatment accorded him by this strange enemy, zoomed the second his
propellers whirred into top-speed action, and raced up the sky toward
the belly of the aero-sub.

"If only the aero-sub has a blind spot!" cried Prester Kleig.

* * * * *

In that instant a roaring crash sounded in the Secret Room as the
American plane, going full speed, crashed, propellers foremost, into the
belly of the aero-sub.

And the aero-sub, whose brothers had seemed until this moment
invincible, did not escape the wrath of the American--though the
American went into oblivion with it!

For, welded together, American plane and aero-sub started the eight
thousand feet plunge downward to the sea!

"Watch!" shrieked Munson. "Watch!"

As the aero-sub and the plane plunged down through the formation of
fighters, the aero-sub pilots saw it, and they fled in wild dismay and
at top speed from their falling compatriot. Why? For a moment it was not
apparent. And then it was.

For out of the body of the doomed aero-subs came sheets of golden flame!
Not the flames of fire, but the golden sheen of that streak which the
aero-subs had used against the American planes already out of the fight!
The American flyer had crashed into the container, whatever it was, that
harnessed the agency through which the minions of Moyen had destroyed
the _Stellar_, and the battleships raped from Hampton Roads!

"It is liquid, then!" shrieked Munson.

And it seemed to be. For a second the golden mantle, strange,
awe-inspiring, bathed and rendered invisible the aero-sub and the plane
which had slain her. Then the golden flame vanished utterly,
instantly--and in the air where it had been there was nothing! The
aero-sub was gone, and the plane whose mad charge had erased her.

"Her own death dealing agency destroyed her!" shrieked Munson. "And the
other aero-subs cut away from the fight to save themselves, because they
too carry