have my authority to
send him right along on his way."

"Right, sir," the technical sergeant answered, and grinned as though he
could name two or three high rankers he would just love to toss out on
their ears, now that he had the permission to do so.

However, he didn't mention that little item. Instead, he snapped orders
to the two mechanics, and all three of them began rolling the attack
bomber out onto the hangar apron. Meanwhile Colonel Welsh led Dawson and
Farmer into Captain Billings' office in a rear corner of the hangar. He
snapped on the light, closed the door, waved them to a couple of chairs,
and sat down at a desk. He drew six envelopes from an inside pocket of
his tunic. Each envelope was heavily sealed with wax, and each was made
of a peculiar-looking paper. At first glance it struck Dawson that it
was oil paper, or shark's skin. At any rate, he had a sudden thought
that each envelope was absolutely waterproof.

The colonel placed them in a pile on the desk in front of him, and then
rested a hand on top of the pile, almost as though he expected a
non-existent wind or an invisible force to snatch them away.

"You two are headed for Natal, Brazil," he began, speaking quietly.
"With stops on the way at Miami, Puerto Rico, San Fernando in British
Trinidad, Paramaribo in Dutch Guiana, Belem in Brazil, and Natal. You
will land on the government airport at each of those points.
Officially, you are making a survey flight for the Army Air Transport
Command. At Miami and Puerto Rico you will contact the American
commanding officer, and deliver to him _in the presence of no one else_
the envelope that bears his name. On the authority of a letter which I
shall give you to take along, you are to instruct him to guard his
envelope with his life, and _not_ to open it until the sixteenth of this
month. At San Fernando, Paramaribo, Belem, and Natal, of course you will
contact the officer in command of the American staff, and not the
commanding officer of the airport."

The colonel paused for a moment as though permitting time for his
instructions to sink in. Then he tapped the pile of heavily sealed,
waterproof envelopes with his fingers.

"These contain information on perhaps the most important secret of this
war!" he continued, speaking in a grave tone. "The Axis would gladly
give up half a dozen divisions of troops for the possession of any one
of these envelopes. And that doesn't even begin to describe how
impo