give us a clue to what's going on here."

At Barby's request, Rick and Scotty took the girls along for the short
ride. Steve's man walked to the plane as they rolled to a stop on the
Falls Church strip. He introduced himself as Don Baxter, then opened the
suitcase he carried. "Let's see what you have."

He produced a field-survey instrument and held it over the bag Rick
carried. The instrument's meter showed a reading at once.

"Gamma," Baxter stated. "Now let's try for alpha and beta." He opened a
shield on the bottom of his instrument and checked the sample again. The
meter failed to respond. "No beta. That's interesting." An inner shield
was slid out of the way and the instrument held to the bag. The meter
responded.

Baxter nodded satisfaction. "Alpha and gamma. No beta. That means this
stuff is not a fission product."

He studied the powder and rubbed a bit between his thumb and forefinger.
He asked, "May I have the bag?"

"Sure," Rick agreed readily. "What is the stuff?"

Baxter took the cement bag and folded it neatly, then he took a plastic
bag from his case and put the cement bag inside. "I can't be sure," he
said. "About its precise identity, I mean. But it seems to be pulverized
ore, and my guess would be carnotite. Don't worry about the
radioactivity. You could live in a house made of this stuff and it
wouldn't be dangerous. The level of activity is very low. I suppose you
have no idea where the sample came from?"

Rick shook his head. "Where does carnotite come from, usually?"

"The Colorado Plateau, for the most part. There are other deposits, but
none around here. This stuff was almost certainly imported. Have you any
idea why?"

"Not the slightest. It's a complete mystery."

Baxter nodded. "Well, that's all I can do for now. I'll analyze the
sample and let Steve Ames know exactly what it is, but I'm betting on
carnotite. If you find a few hundred tons of it, you can sell it to the
Atomic Energy Commission. So long."

The expert tipped his hat to the girls and walked to his car.

"What was that all about?" Barby demanded. "You and Scotty seemed to
know what he was talking about, but it was all Greek to Jan and me."

Rick explained on the way back to the farm. "There are four main kinds
of radioactivity. They're called alpha, beta, gamma, and neutrons. Our
sample has alpha and gamma. That means it doesn't come from either bomb
debris or from a reactor, because fission takes place in both,