ped. "It looks like the Nazis have made a
play for that formula already! I've got to get right back to the
laboratory!"

Henry and the professor still were excitedly discussing this news when,
half an hour later, the 'phone rang again. This time the tall scientist
answered. He returned to the porch frowning.

"That was Coggleston," he reported. "Apparently the spy didn't get the
formula, but he made a clean getaway, and he killed a sentry to do it."

"Oh, that's terrible!" Henry was afire with indignation. "Of all things!
Killing a sentry--"

"Yes." The professor nodded. "The trouble is, Coggleston says they don't
have much to go on. No description, except that he was big and had red
hair--"

"Red hair!"

"Yes. Red hair." The savant eyed Henry suspiciously. "Why does that
surprise you so?"

"Why ... er ... oh, it doesn't. I mean--"

"What do you mean?"

"Really, Joseph, it's nothing." The little man squirmed nervously, his
goatee hanging guiltily to one side. "I'm not surprised at all. Really
I'm not!"

"Oh, you're not, aren't you?" Professor Paulsen started across the room
with grim determination, his eyes sharp. "Well, then--"

"Joseph--"

The scientist reached for his colleague's shoulder. But the shoulder
slipped away. Henry dived frantically for the doorway.

"Oh, no, you don't!"

* * * * *

Spinning about with surprising agility, the professor's hand speared
out. It stabbed home to its goal on Henry's chin with deadly aim. Caught
the little man's goatee in a grip that stopped his headlong rush dead
still.

"Joseph!" screamed Henry, his eyes filling with tears. "Stop it! You're
hurting!"

"And I intend to keep right on hurting until I get the truth out of you,
you amoeba-brained atom!" thundered the other. "I can smell your lies a
block away--and this is one time you're not going to get away with it!
Now: tell me who the red-headed man was."

"I don't know, Joseph! Really--"

Professor Paulsen gave his colleague's chin-whiskers a savage jerk.

"I want the truth!" he rapped. "Hurry up! Tell me!" He jerked again.

"Oh! Ow! Joseph, please! Oh, let me go! I'll tell--"

"You bet you'll tell!" grated his friend. "It's one thing to let you get
away with making a fool of me. But when it comes to tampering with the
United States Army--" And then, breaking off: "All right. Why did you
jump so when I mentioned the spy was believed to have red hair?"

"Well...." He