al from which a
fiery-tongued orator was addressing them. Lounging negligently at the
edge of the small crowd were a dozen of the red police.

"I tell you, comrades," the speaker was shouting, "the time has come
when we must revolt. We must battle to the death with the wearers of the
purple. Why work out our lives down here so they can live in the lap of
luxury over our heads? Why labor day after day at the oxygen generators
to give them the fresh air they breathe?"

The speaker paused uncertainly as a chorus of raucous laughter came to
his ears. He glared belligerently at a group of newcomers who stood
aloof from his own gathering. Seven or eight of them there were, and
they wore the gray with obvious discomfort. Slummers! Well, they'd hear
something they could carry back with them when they returned to their
homes!

"Why," he continued in rising tones, "do we sit at the controls of the
pneumatic tubes which carry thousands of our fellows to tasks equally
irksome, while they of the purple ride their air yachts to the pleasure
cities of the sky lanes? Never in the history of mankind have the poor
been poorer and the rich richer!"

"Yah!" shouted a disrespectful voice from among the newcomers. "You're
full o' bunk! Nothing but bunk!"

An ominous murmur swelled from the crowd and the red police roused from
their lethargy. The mounting scream of a siren echoed in the vaulted
recesses above and re-echoed from the surrounding columns--the call for
reserves.

* * * * *

All was confusion in the Square. The little group of newcomers
immediately became the center of a melee of dangerous proportions. Some
of the more timid of the wearers of the gray struggled to get out of the
crowd and away. Others, not in sympathy with the speaker, rushed to the
support of the besieged visitors. The police were, for the moment,
overwhelmed.

The orator, mad with resentment and injured pride, hurled himself into
the group. A knife flashed in his hand; rose and fell. A scream of agony
shrilled piercingly above the din of the fighting.

Then came the reserves, and the wielder of the knife turned to escape.
He broke away from the milling combatants and made speedily for the
shadows that lay beyond the great pillars of the Square. But he never
reached them, for one of the red guards raised his riot pistol and
fired. There was a dull _plop_, and a rubbery something struck the
fleeing man and wrapped powerfu