, in the rack near the metal cup where the punk still
glowered.

All at once, a glare of light burst upward through the white-glowing
mist; and the 'plane reeled with the air-wave, as now a thunderous
concussion boomed across the empty spaces of the sky.

At the same moment, a faint, ripping noise mounted to Gabriel--a sound
for all the world like the tearing of stout canvas. Then followed a
chattering racket, something like distant mowing-machines at work; and
now all blent to a steady, determined uproar. Gabriel almost thought to
hear, as he launched his own projectile, far sounds as of the shouts and
cries of men; but of this he could not make sure.

"They're at it, anyhow!" he exulted. "At it, at last! By the way our men
have launched the attack, the first explosion must have breached a wall!
God! What wouldn't I give to be down there, in the thick of it, rather
than here! I--"

_Crash_!

Again a spouting geyser of light and uproar burst into mid-air.

"That was _my_ thanatos speaking!" cried Gabriel. "Now for another!"

Before he could drop it, as he circled round and round, directly over
the great, flailing beams of the Air Trust search-lights, a third
detonation shattered the heavens, nearly unseating him. Up sprang the
roar, with wonderful intensity, reflected from the earth as from a giant
sounding-board. And Gabriel noted, with keen satisfaction, that one of
the huge light-beams had gone dark.

"Put out _one_ of them, anyway, so far!" thought he, and swung again to
westward, and once more dropped a messenger of death to tyranny.

Now the bombardment became general. Trust aerial-gun projectiles began
bursting all about. Every second or two, terrible concussions leaped
toward the zenith; and the earth, hidden somewhere down there below the
fog-blanket, seemed flaming upward like a huge volcano. One by one the
search-lights, whipping the sky, went black; and now the glow of them
was fast diminishing, only to be replaced by a ruddier and more
intermittent glare.

"The plant's burning, at last," thought Gabriel. "Heaven grant the fire
may spread to the oxygen-tanks! If we can only get _those_--!"

Again he launched a projectile, and again he circled over the doomed
plant.

A swift black shape swooped by him. He had just time to exchange a yell
of warning, when it was gone. The near peril gripped his heart, but did
not shake it.

"Close call!" said he.

If that machine and his had met, good-bye for