ourselves! Quick, Waldron, quick!"

Both men, sick with panic, with fear of the unknown terror from above,
stumbled rather than ran along the passage, and presently reached the
laboratory.

Here Waldron unlocked another door, this time a steel one, and--as they
both crowded through--pressed a hand to his dizzy head.

"Safe!" he gulped, slamming the door again. "They can't get us _here_,
at any rate, no matter what happens! This place is like a fort, and--"

His speech was interrupted by a dazing, deafening tumult of sound. The
earth trembled, and the laboratory, steel though it was, with concrete
facing, rocked on its foundation. A glare through the windows, quickly
fading, told them the building they had just quitted was now but a
smoking pile of ruin.

Flint gasped, unable to speak. Waldron, shaking and cowed, tried to
moisten his dry lips with a thick tongue.

"We--we weren't any too soon!" he gulped, without one thought of the
doomed scabs in the Administration Building. Stern justice was now
overtaking these wretches. False to the working-class, and eager to
serve the Air Trust--not only eager to serve, but zealous in any attack
on the proletariat, and by their very employment serving to rivet the
shackles on the world--now they were abandoned by their masters.

Between upper and nether millstone, moving with neither, they were
caught and crushed. And as the great building quivered, gaped wide
open, swayed and came thundering down in a vast pile of flame-lit ruin,
whence a volcanic burst of fire, smoke and dust arose, they perished
miserably, time-servers, cowards and self-seekers to the last.

But Flint and Waldron still survived. Though the very earth shook and
trembled with the roar of bombs, the crumbling of massive walls, the
rattle of volley-fire and the crashing of the terrible grenades that
mowed down hundreds as they spread their poisonous gas abroad--though
the shriek of projectiles, the thunder of the air-ship guns now sweeping
the sky in blind endeavor to shatter the attackers all swelled the
tumult to a frightful storm of terror and of death; they still lived,
cowered and cringed there in the bomb-proof steel-and-concrete of the
inner laboratories.

"Come, come!" Flint quavered, peering about him at the deserted room,
still glaring with electric light--the room now abandoned by all its
workers, who, members of Herzog's regiment, had run to take their posts
at the first signal of attack. "Come