before the overwhelming Slavish troops.

Even now, as Lance knew through various rumors, the Slavs were massed
for a grand attack. And with what could America hold them back?

His helicopter props spun, and the scout nestled down lightly on the
tarmac. Lance switched off the faithful Rahl-Diesels, swung open the
tiny door and leaped from the enclosed cockpit.

"Sir," he rapped to thin, stern-browed Colonel Douglas, "there's no
longer any doubt in my mind. This is the fifth time we've been
anticipated--trapped! The enemy is informed directly of the attacking
plans of our scout details. There's a spy at this base!" He lowered
his eyes for a second and said in a queer tone of voice: "Thirteen of
'em went down to-day."

Colonel Douglas' tired face showed the never-ceasing strain he was
under. He clasped hands behind his back, took a few nervous turns up
and down the small office and finally, with a somewhat hopeless sigh,
muttered:

"I know, Lance, I know. The devils! They seem to be aware of
everything we plan. Yet what can we do? Look at the territory our
front lines cover! More than two thousand miles of loosely held
ground. And we're so damnably organized, man! Look here!"

* * * * *

He strode to the huge map which covered entirely one wall of the
little room and ran his forefinger down the long red line, signifying
the American front, which stretched crookedly from the Canadian border
to the Gulf of California. Parallel to it was another line, of
black--the United Slavs.

"It's so damned easy," Colonel Douglas said, "for a spy to slip over."
He sighed again. "I fought in the scrap of 1917 as a kid of twenty; it
was different then. But this is 1938, and it's a scientific war we're
trying to fight." He sat down in his swivel chair. "How--how did they
wipe you out to-day?"

"That blasted disintegrating flame again," Lance told him swiftly.
"It's obvious, Colonel: how did the Slavs know we were going to raid
that comparatively unimportant base of theirs at such and such a time?
They had the flame shooters all ready for us--and at a place where
they've never had them before! We came up at twenty-five thousand
feet, dropped down in a full power dive, and"--he gestured
widely--"biff! The flames caught us neatly at the regulation thousand
feet. They got thirteen men. Only two got away, Praed and myself."
His keen eyes were inquiring, and the colonel interpreted their look
correctly.