simple; all we had to do was handle them a bit. And we watched what happened.

They died—of young age.

Some vital organ or another regressed to embryonic condition, and they died—as Greco and I would die, if we didn't find the answer. As the whole world might die. Was it better than reverting past the embryo to the simple lifeless zygote? I couldn't decide. It was dying, all the same. When an embryonic heart or liver is called on to do a job for a mature organism, there is only one way out. Death.

And after death—the demons went on; the dog we fed on the remains of the guinea pigs followed them to extinction in a matter of weeks.

Minnie was an interesting case.

She was going about her work with more energy every day, and I'll be blasted if I didn't catch her casting a lingering Marilyn Monroe sort of look at me when Greco's back was turned.

"Shall we fire her?" I asked El Greco when I told him about it.

"What for?"

"She's disrupting the work!"

"The work isn't worth a damn anyhow," he said moodily. "We're not getting anywhere, Virgie. If it was only a matter of smooth, predictable rates—But look at her. She's picking up speed! She's dropped five years in the past couple weeks."

"She can stand to drop a lot more," I said, annoyed.

e shrugged. "It depends on where. Her nose? It's shortened to about a fifteen-year-old level now. Facial hair? That's mostly gone. Skin texture? Well, I suppose there's no such thing as a too-immature skin, I mean short of the embryonic capsule, but—Wait a minute."

He was staring at the doorway.

Minnie was standing there, simpering.

"Come here!" he ordered in a voice like thunder. "Come here, you! Virgie, look at her nose!"

I looked. "Ugh," I said, but more or less under my breath.

"No, no!" cried Greco. "Virgie, don't you see her nose?" Foolish; of course I did. It was long, beaked—

Then I saw.

"It's growing longer," I whispered.

"Right, my boy! Right! One curve at least has reversed itself. Do you see, Virgie?"

I nodded. "She's—she's beginning to age again."

"Better than that!" he crowed. "It's faster than normal aging, Virgie! There are aging demons loose too!"

A breath of hope!

But hope died. Sure, he was right—as far as it went.

There were aging demons. We isolated them in some of our experimental animals. First we had to lure Minnie into standing still while Greco, swearing horribly, took a tissue sample; she didn't like that, but a hundred-dollar bonus converted her. Solid CO₂ froze the skin; snip, and a tiny flake of flesh came out of her nose at the point of Greco's scalpel; he put the sample of flesh through a few tricks and, at the end of the day, we tried it on some of our mice.

They died.

Well, it was gratifying, in a way—they died of old age. But die they did. It took three days to show an effect, but when it came, it was dramatic. These were young adult mice, in the full flush of their mousehood, but when these new demons got to work on them, they suddenly developed a frowsy, decrepit appearance that made them look like Bowery bums over whom Cinderella's good fairy had waved her wand in reverse. And two days later they were dead.

"I think we've got something," said Greco thoughtfully; but I didn't think so, and I was right. Dead was dead. We could kill the animals by making them too young. We could kill the animals by making them too old. But keep them alive, once the demons were in them, we could not.

Greco evolved a plan: Mix the two breeds of demons! Take an animal with the young-age demons