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 much. But bear in mind that this is simply the most trifling application of my discovery. I could use it for separating U-235 from U-238 just as easily. In fact, I already—" He stopped in mid-sentence, cocked his head, looked at me and backtracked. "Never mind that. But you know what a Maxwell demon is?"

"No."

"Good for you, Virgie. Good for you!" he applauded. "I knew I'd get the truth out of you if I waited long enough." Another ambiguous remark, I thought to myself. "But you surely know the second law of thermodynamics."

"Surely."

"I thought you'd say that," he said gravely. "So then you know that if you put an ice cube in a glass of warm water, for instance, the ice melts, the water cools, and you get a glass with no ice but with all the water lowered in temperature. Right? And it's a one-way process. That is, you can't start with a glass of cool water and, hocus-pocus, get it to separate into warm water and ice cube, right?"

"Naturally," I said, "for heaven's sake. I mean that's silly."

"Very silly," he agreed. "You know it yourself, eh? So watch."

He didn't say hocus-pocus. But he did adjust something on one of his gadgets.

There was a faint whine and a gurgling, spluttering sound, like fat sparks climbing between spreading electrodes in a Frankenstein movie.

The water began to steam faintly.

But only at one end! That end was steam; the other was—was—

It was ice. A thin skin formed rapidly, grew thicker; the other open end of the U-tube began to bubble violently. Ice at one end, steam at the other.

Silly?

But I was seeing it!

I must say, however, that at the time I didn't really know that that was all I saw.

he reason for this is that Pudge Detweiler came groaning down the steps to the laboratory just then.

"Ah, Greek," he wheezed. "Ah, Virgie. I wanted to talk to you before I left." He came into the room and, panting, eased himself into a chair, a tired hippopotamus with a hangover.

"What did you want to talk to me about?" Greco demanded.

"You?" Pudge's glance wandered around the room; it was a look of amused distaste, the look of a grown man observing the smudgy mud play of children. "Oh, not you, Greek. I wanted to talk to Virgie. That sales territory you mentioned, Virgie. I've been thinking. I don't know if you're aware of it, but when my father passed away last winter, he left me—well, with certain responsibilities. And it occurred to me that you might be willing to let me invest some of the—"

I didn't even let him finish. I had him out of there so fast, we didn't even have a chance to say good-by to Greco. And all that stuff about demons and hot-and-cold water and so on, it all went out of my head as though it had never been. Old Pudge Detweiler! How was I to know that his father had left him thirty thousand dollars in one attractive lump of cash!

II

ell, there were business