ers go with you!"

One hour had passed since Moyen's ultimatum when the first vanguard of
the American flyers, obeying the peremptory signal, took the air and
darted eastward to meet the winged death-harbingers of Moyen.

CHAPTER X

"_They Shall Not Pass!_"

Prester Kleig's heartfelt desire, as the American flyers closed with the
first of the aero-subs, was to go out with them and aid them in the
attack against the Moyenites. But he knew, and it was a tacit thing,
that he best served his country from the safe haven of the Secret Room.

As he watched the scenes unfold on the screen of Maniel's genius, with
occasional glances at the somewhat mysterious but profound and
concentrated labors of Maniel, Charmion Kane rose from her place and
came to his side.

Wide-eyed as she watched the joining of battle, she stood there, her
tiny hand encased in the tense one of Prester Kleig.

"You would like to be out there," she murmured. "I know it! But your
country needs you here--and I have already given Carlos!"

Prester Kleig tightened his grip on her hand.

* * * * *

There was deep, silent understanding between these two, and Prester
Kleig, in fighting against the Moyenites, realized, even above his
realization that his labors were primarily for the benefit of his
country, that he really matched wits with Moyen for the sake of
Charmion. Had anyone asked him whether he would have sacrificed her for
the benefit of his country, it would have been a difficult question to
answer.

He was glad that the question was never asked.

"Yes, beloved," he whispered, "I would like to be out there, but the
greatest need for me is here."

But even so he felt as though he was betraying those intrepid flyers he
was sending to sure death. Yet they had volunteered, and it was the only
way.

Maniel, a gnomelike little man with a Titan's brain, labored with his
calculations, made swiftly concrete his theories, while at the
Sound-and-Vision apparatus excitable General Munson ranged the aerial
battlefield to see how the tide of battle ebbed and flowed.

That neither side would either ask or give quarter was instantly
apparent, for they rushed head-on to meet each other, those vast
opposing winged armadas, at top speed, and not a single individual
swerved from his course, though at least the Americans knew that death
rode the skyways ahead.

Then....

The battle was joined. Moyen's forces were s