th.

"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 CO_{2} 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 already in it, then add a batch that worked
in the other direction!

* * * * *

For a while, it seemed to work--but only for a while. After a couple
of weeks, one breed or the other would gain the upper hand. And the
animals died.

It was fast in mice, slow in humans. Minnie stayed alive. But the nose
grew longer and facial hair reappeared; simultaneously her complexion
cleared, her posture straightened.

And then, for the first time, we began to read the papers.

STRANGE PLAGUE
STRIKES ELGIN

bawled the Chicago _Tribune_, and went on to tell how the suburbs
around Elgin, Illinois, were heavily infested w