ward a towering rampart at
the heart of it, crowned with huge domes and minarets and serpentine
ramps and mighty blocks of stone that must have sheltered as many
occupants as New York's highest skyscrapers.

The whole was snow-white, and gleamed softly in an artificial light
dispensed from an enormous artificial planet that seemed to hover
above the ramparts.

"God!" whispered Jim in awe as he gazed at the great city.

"You cannot cross that causeway," whimpered old Parrish. "It's death
to try. One sweep of the Ray will blot out every living thing."

"Hush! Listen!" came from Lucille's lips. "Something's moving down
there!"

* * * * *

The distant murmur of voices, the indescribable "feel" of the
proximity of other human beings told Jim that they were in imminent
danger. He glanced about him. A little overhead was an outcrop of
enormous boulders, standing up like a little fortress above the smooth
lava.

"Get behind there!" Jim whispered.

They turned and ran, slipping and stumbling up the smooth slope.
Reaching the boulders, they ensconced themselves hastily behind them.
Jim peered out through a crevice between two of the largest stones.
The sound of moving things became more audible.

Then, as a flash of flame shot from the crater overhead, Jim saw a
black human horde creeping like an array of ants around the base of
the mountain not far beneath.

Just like an army of warrior ants it seemed to flow onward, in perfect
order. And in the midst of it a faint violet light began to be
visible.

Parrish seized Jim's arm, shaking with terror. "You know what that is,
Dent?" he whimpered.

"It's Tode's Drilgoes, moving for a night attack upon Atlantis,"
answered Jim. "And that thing in the middle is the Atom Smasher."

* * * * *

It seemed hours before the last of the serried ranks of Drilgoes had
passed. By the light of a lurid flash from the volcano Jim could see
the column winding toward the causeway. Then all was shrouded in
impenetrable darkness, save for the snow-soft city upon the island.

"What are we going to do?" chattered old Parrish. "I wish I was back
in Tode's cave. He gave me food and let me help with his work
sometimes. I'll die here. We'll never get away. We'll never get
anywhere."

"We're safer here than anywhere else," answered Jim. "We'll have to
stay till morning, or--God, look at that!"

Out of the ramparts of the city th