question, Dawson," Colonel Welsh said with an emphatic
nod. "Just shows you've got your eye on the ball right at the start.
Contact the officer, show him my letter of authority, and demand his
identification. It will be a copper disc with some numbers stamped on
it. Every set of numbers will add up to forty-one--the year,
incidentally, of Pearl Harbor. If the numbers don't add up to forty-one,
then he is not your man."

"And if they _don't_ add up to forty-one, sir?" Freddy Farmer asked, and
leaned forward.

Colonel Welsh's lips stiffened, and an agate-hard glint came into his
eyes. He pointed to the letter of authority Freddy held in his hands.

"Use that to have the man placed under close arrest at once!" he said
harshly. "And get in radiophone communication with me as soon as
possible. _If_ the man tries to evade arrest, tries to escape--shoot him
dead on the spot! Yes, that's an unusual order, but this is an unusual
mission. Now, the other question, Dawson? What is it?"

"When we reach Natal, sir," Dave said, "what do we do? Fly back and
report to you?"

"No," the senior officer said with a shake of his head. "I'm allowing
three days for you to make this stop-over flight to Brazil. That should
get you in Natal by the fourteenth, the fifteenth at the latest. Put up
at the Pan-Am Hotel. I will join you there on the fifteenth. I'll have
another little mission for you when I get there. Well, any other
questions?"

Dawson and Farmer looked at each other. Then they looked at Colonel
Welsh, and each shook his head. The senior officer stood up, and as
though the gods had waited for that exact instant, the Vultee's
Wright-Cyclone outside broke forth with its song of mighty power.

"Then that's that," Colonel Welsh said. "There's some flying gear over
there on the wall. Select what you want, and then let's get outside to
the plane. I'll stake my life that not a soul has heard what we've been
talking about, but four walls always get on my nerves. I like it better
out in the open where I can see in all directions, and for some
distance, too. But don't pay any attention to me. I'm under a slight
strain, and it's trying its darnedest to get me. Stupid, of course. So
select your stuff, and let's get out to the plane. God bless you, and
all kinds of happy landings until we meet again in Natal, Brazil."

If they happened to be listening to the colonel's parting words, the
gods of war, and death, and doom, must have had quit