and here some fifty per cent of those stricken had suffered paralysis
instead of death.

But a new element had been injected into the situation. Even the
heroic courage shown by the populace in the beginning had had its
limits. The morning after the news of the Invisible Death's advent was
made public mobs had gathered in all the large cities of the East,
demanding surrender.

The submerged elements of crime and disorder had come to the surface
at last. Committees were formed, with the avowed object of yielding to
the Invisible Emperor, and averting further disaster. In Washington, a
city of the dead, half the members of Congress and the Senators had
gathered in the ruined Capitol, to debate the situation.

There were rumors of an impending march on the White House, of a coup
d'etat.

* * * * *

The action of the Government was prompt. Five hundred loyalists were
enrolled, armed, and posted round the White House: every avenue of
approach was commanded by machine-guns. Meanwhile the news was spread
by radio that the headquarters of the Invisible Emperor had been
located, and that a strong bombing squadron was being dispatched to
destroy it.

The entire fleet was to follow, and it was confidently anticipated
that within a little while the Terror would be at an end.

Those at the white House were less sanguine. There was none but
realized the diabolical strength of their antagonists.

"Everything depends upon the outcome of the next forty-eight hours,
and everything depends on you, Rennell," said Secretary Norris to
Dick, as he stood beside his plane. Behind him his flight of a dozen
airships was drawn up.

"Find them," added the Secretary; "cover Abaco Island with the black
gas, and the navy and the marines will wipe up the mess that you leave
behind you. God help you--and all of us, Rennell!"

He gripped Dick's hand and turned away. Dick was very sober-minded as
he climbed into his cockpit. He knew to the full how much depended
upon himself and Luke Evans. Already the shouts of the insurgents were
to be heard at the ends of the barriers, commanded by the
machine-guns, and patrolled by the enlisted volunteers.

Negro mobs were building counter-barricades of their own with rubble
from the fallen edifices. Civil war might be postponed for
eight-and-forty hours, but after that unless there was news of
victory, the whole structure of civilization would be smashed
irreparably.

I