showed this to
be a method of control. Other spots shone dark and glassy. Were they
windows? He hardly realized their peril, so interested was he in the
strange machine ahead.

* * * * *

Then: "Dodge that vapor," ordered General Lozier. The plane wavered in
signal to the others and swung sharply to the left. Each man knew the
flaming death that was theirs if the fire of their exhaust touched that
explosive mixture of hydrogen and air. The great bubble turned with them
and paralleled their course.

"He's watching us," said Riley, "giving us the once over, the slimy
devil. Ain't there a gun on this ship?"

The General addressed his superior. Even above the roar of the motors
his voice seemed quiet, assured. "We must not land now," he said. "We
can't land at North Island. It would focus their attention upon our
defenses. That thing--whatever it is--is looking for a vulnerable spot.
We must.... Hold on--there he goes!"

The big bulb shot upward. It slanted above them, and hovered there.

"I think he is about to attack," said the General quietly. And, to the
commander of their squadron: "It's in your hands now, Captain. It's
your fight."

The Captain nodded and squinted above. "He's got to throw heavier stuff
than that," he remarked. A small object was falling from the cloud. It
passed close to their ship.

"Half-pint size," said Cyrus Thurston, and laughed in derision. There
was something ludicrous in the futility of the attack. He stuck his head
from a window into the gale they created. He sheltered his eyes to try
to follow the missile in its fall.

* * * * *

They were over the city. The criss-cross of streets made a grill-work of
lines; tall buildings were dwarfed from this three thousand foot
altitude. The sun slanted across a projecting promontory to make golden
ripples on a blue sea and the city sparkled back in the clear air. Tiny
white faces were massed in the streets, huddled in clusters where the
futile black missile had vanished.

And then--then the city was gone....

A white cloud-bank billowed and mushroomed. Slowly, it seemed to the
watcher--so slowly.

It was done in the fraction of a second. Yet in that brief time his eyes
registered the chaotic sweep in advance of the cloud. There came a
crashing of buildings in some monster whirlwind, a white cloud engulfing
it all.... It was rising--was on them.

"God," thought Thurston, "w