olden flames, blinding in their brightness, dropping down, mere
shapeless blotches, then fading out to nothingness in a matter of
seconds--with aero-sub and airplane totally erased from action and from
existence.

The American flyers saw and knew now the manner of death they faced. Yet
all along the battle front not an American tried to evade the issue and
draw out of the fight. A sublime, inspiring exhibition of mass courage
which had not been witnessed down the years since that general
engagement which men of the time had called the Great War.

Prester Kleig turned to look at Maniel. Drops of perspiration bathed the
cheeks of the master scientist, but his eyes were glowing like coals of
fire. His face was set in a white mask of concentration, and Prester
Kleig knew that Maniel would find the answer to the thing he sought if
such answer could be found.

Would the American flyers be able to hold off the minions of Moyen until
Maniel was ready? The fight out there above the waters was a terrible
thing, and the Americans fought and died like men inspired, yet
inexorably the winged armada of Moyen, preceded by those licking golden
tongues, was moving landward.

"Great God!" cried Munson. "Look!"

* * * * *

There was really no need for the order, for every Secret Agent saw as
soon as did Munson. Under the sea, just off the coast, the mother-subs
had touched their blunt nose against the upward shelving of the sea
bottom--had touched bottom, and were slowly but surely following the
underwater curve of the land, up toward the surface, like unbelievable
antediluvian monsters out of some nightmare.

"Yes," said Kleig quietly, "those monsters of Moyen can move on land,
and the aero-subs can operate from them as easily on land as under
water."

Kleig regarded the time, whirled to look at Professor Maniel.

One hour and forty minutes had passed since Maniel had begged for two
hours in which to prepare some mode of effectively combatting the might
of Moyen. Twenty minutes to go; yet the mother-subs would be ashore,
dragging their sweating, monstrous sides out of the deep, within ten
minutes!

Ten minutes ashore and there was no guessing the havoc they could cause
to the United Americas!

"Hurry, Maniel! Hurry! Hurry!" said Prester Kleig.

But he spoke the words to himself, though even had he spoken them aloud
Maniel would not have heard. For Maniel, for two hours, had closed his
mind t