to Lance's.

"Yes, it's true. The man you knew as Praed in reality is Captain Hay.
You see, Lance, headquarters was taking no chances with what I just
called the Torpedo Plan. Every move had to be conducted with the
utmost secrecy. Had to be! For the Torpedo Plan is, in some ways,
America's last hope.

"Our base, No. 5, was chosen as the center of activity, the base from
which the steps paving the way for the plan would be taken. The two
best pilots in the service were needed. You and Hay were chosen.

"It was decided it would be best to mask Hay's real identity. So,
officially, he was sent to the hospital; in reality he came here,
under the name of Praed. Why? Because there's a spy somewhere--we
don't seem to be able to track him; he's infernally clever--and if the
famous Captain Hay was switched to Base 5, putting the two best
pilots in the service together, that spy'd know something was in the
air. Understand?"

Lance nodded dumbly. A great light was beginning to shower him.

"To more completely mask our true purpose," the colonel continued,
"Hay was instructed to make it appear as if he were a spy. And it was
a damned hard job! The real spy, whoever he is, and wherever he is,
would thus be additionally fooled; for all he'd know, the Slavs might
have sent another over to back him up. That's why Hay never shot down
an enemy plane. Says something about his skill as a pilot, doesn't it?
Never able to defend himself, save by maneuvering. He's a great
flyer!"

Lance could only nod dumbly again.

"After a couple of weeks at this base," Douglas went on, "Hay was to
cross the lines one night with you accompanying him. You,
unintentionally, would thus occupy the enemy planes while Hay attended
to the real business of the evening. And you did splendidly!"

"The real business?" Lance questioned. "What the devil was that? I
thought the real business was to get the dope on Hill 333."

"So it was--partially. But also to take the first step of the Torpedo
Plan, which was for Hay to switch over to a Slav plane."

_"What?"_

* * * * *

The colonel repeated his statement, somewhat dryly. Lance's square jaw
dropped abruptly. "But--but--" he exclaimed, "how the devil could he
do that?"

Colonel Douglas grinned.

"By a very neat contraption from the brain of one of our most valuable
scientists," he explained. "Hay's scout was specially fitted up before
you left; while you were sleeping, i