the colonel would hurry up and get here!"

"Know something, Dave?" Freddy asked after a couple of moments of
silence between them.

"_Know_ something?" Dave groaned, and rolled over on his stomach. "Maybe
you haven't been listening to me, pal. _I_ don't know from nothing. Do
you?"

"Not exactly," Freddy replied. "Just the old guessing game again. I am
guessing, though, that somebody found out about those sealed envelopes.
Also, they found out that you and I were acting as the messenger boys.
Also, they arranged that balmy life-raft and U-boat business this
afternoon. And also, Colonel Welsh is a very worried man, right at the
moment."

"All of which means nothing," Dawson added, "and will continue to mean
nothing until the colonel gets here, and explains. _If_ he does."

"Most naturally!" Freddy said with a slight edge to his voice. "I've
been doing some extra thinking about this thing, in case you don't
realize it."

"Well, go right ahead and think yourself black, blue, and sky-pink in
the face, if it makes you happy, little man," Dawson said with a laugh,
"but you still won't know from beans until the colonel gets here. And if
he--"

"I know, _I know_!" Freddy interrupted with an impatient gesture of his
hand. "Save your breath, old thing. However, you might give this a bit
of thought, if your brain can stand the strain. We've been flying part
of the air transport route to North Africa."

"No kidding?" Dawson said with a mock gasp. "Why, I always thought the
air transport route to North Africa was by way of Salt Lake City and
Alaska!"

"Very, _very_ funny!" Freddy snapped. "If I'm not boring you, Major
Parker said he was sent down here to keep an eye out for sabotage. He
also said nothing has happened in all the time he's been here. Colonel
Welsh admitted that his special agents were acting as C.O. of the points
where we've stopped and were going to stop. Why, Dave? _Why_ should
Intelligence have a sudden interest in this air route to North Africa?"

Dawson started to make another wisecrack, but the deadly serious look on
young Farmer's face stopped him. He gave the question a moment or two of
thought and then shook his head.

"I don't know, Freddy," he replied. "I really don't know. You can search
me. If it isn't because of possible sabotage, then what?"

"I guess I've asked myself that question a thousand times," the
English-born air ace said slowly. "I can think up but one answer that
might make se