“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—­this isn’t safe enough, even here.  In—­in there!”

He pointed toward a vault-like door, leading to the subterranean steel chambers where Herzog eventually counted on storing some hundreds of thousands of tons of liquid oxygen—­the reserve-chambers, impregnable to lightning, fire, frost or storm, to man’s attacks or nature’s—­the chambers blasted from the living rock, deep as the Falls themselves, vacuum-lined, wondrous achievement of the highest engineering skill the world could boast.

“There!  There!” repeated Flint, plucking at the dazed Waldron’s sleeve.  “Tool-steel and concrete, twenty-five feet thick—­and vacuum chambers all about—­there we can hide!  There’s safety!  Come, come quick!”

Staring, white-faced (he who had been so red!) and dumb, Waldron yielded.  Together, furtive as the criminals they were, these two world-masters slunk toward the steel door, while without, their empire was crashing down in smoke, and flame, and blood!

They had almost reached it when a smash of glass at the far end of the laboratory whipped them round, in keener terror.

Staring, wild-eyed, they beheld the crouching figure of Herzog.  Running, even as he cringed, he had upset a glass retort, which had shattered on the concrete floor.  And as he ran, he screamed: 

“They’re in!  They’re coming!  Quick—­the steel vaults!  Let me in, there!  Let me in!”