Dr. Smith, of course, had been interrogated briefly when he had turned himself in at USAF Western Division Headquarters. But only the General and Amos Busch had questioned him this time.

"Look, Smith," said Amos, "if we're supposed to protect you, I want to know from what—and why it's necessary...."

John O'Hara Smith looked almost embarrassed.

"I suppose I made the same error that is so often made in declassifying information...."

"How's that?"

"When information is declassified, it's done without mathematically computing the infinite number of possible ways such information may be useful to a hostile government.... Of course, you need an Eddie to make such a computation!"

"What's this got to do with trying to knock you off?" Busch demanded.

"It's quite evident that someone read my article in the Research Engineers' journal more carefully than you did! As a matter of fact, Eddie actually warned me that anyone hostile to the United States could not possibly allow my work to continue!"

Amos Busch and General Sanders exchanged wary glances.

"All right," said General Sanders, "We'll let that go for the moment—but what made you ask about the X-15 in the first place?"