said.

"All right." He poured water out of a beaker into a U-shaped tube,
open at both ends. "Watch," he said. "Remember any of your college
physics?"

"The way things go, I haven't had much time to keep up with--"

"All the better, all the better," he said. "Then you won't be able to
steal anything."

I caught my breath. "Now _listen_--"

"No offense, Virgie," he said earnestly. "But this is a billion
dollars and--No matter. When it comes right down to cases, you could
know as much as all those fool professors of ours put together and it
still wouldn't help you steal a thing."

He bobbed his head, smiled absently and went back to his gleamy
gadgets. I tell you, I _steamed_. That settled it, as far as I was
concerned. There was simply no excuse for such unjustified insults to
my character. I certainly had no intention of attempting to take any
unfair advantage, but if he was going to act that way....

He was asking for it. Actually and literally asking for it.

He rapped sharply on the U-tube with a glass stirring rod, seeking my
attention.

"I'm watching," I told him, very amiable now that he'd made up my mind
for me.

"Good. Now," he said, "you know what I do here in the plant?"

"Why--you make fertilizer. It says so on the sign."

"Ha! No," he said. "That is a blind. What I do is, I separate optical
isomers."

"That's very nice," I said warmly. "I'm glad to hear it, Greek."

"Shut up," he retorted unexpectedly. "You don't have the foggiest
notion of what an optical isomer is and you know it. But try and
think. This isn't physics; it's organic chemistry. There are compounds
that exist in two forms--apparently identical in all respects, except
that one is the mirror image of the other. Like right-hand and
left-hand gloves; one is the other, turned backwards. You understand
so far?"

"Of course," I said.

* * * * *

He looked at me thoughtfully, then shrugged. "No matter. They're
called d- and l-isomers--d for dextro, l for levo; right and left, you
see. And although they're identical except for being mirror-reversed,
it so happens that sometimes one isomer is worth much more than the
other."

"I see that," I said.

"I thought you would. Well, they can be separated--but it's expensive.
Not my way, though. My way is quick and simple. I use demons."

"Oh, now, Greek. _Really._"

He said in a weary tone, "Don't talk, Virgie. Just listen. It won't
tire you so muc