"What right have you to relax," Mary said. "Outside, people are dying by
the thousands and you want to relax. Have you looked at the latest
mortality reports?"

"No--"

"You should. The WHO estimates that nearly two billion people have died
since Thurston's Disease first appeared in epidemic proportions. That's
two out of three. And more are dying every day. Yet you want to relax."

"I know," Kramer said, "but what can we do about it. We're working but
we're getting no results."

"You might use that brain of yours," Mary said bitterly. "You're
supposed to be a scientist. You have facts. Can't you put them
together?"

"I don't know." He shrugged, "I've been working on this problem longer
than you think. I come down here at night--"

"I know. I clean up after you."

"I haven't gotten anywhere. Sure, we can isolate the virus. It grows
nicely on monkey lung cells. But that doesn't help. The thing has no
apparent antigenicity. It parasitizes, but it doesn't trigger any immune
reaction. We can kill it, but the strength of the germicide is too great
for living tissue to tolerate."

"Some people seem to be immune."

"Sure they do--but why?"

"Don't ask me. I'm not the scientist."

"Play like one," Kramer growled. "Here are the facts. The disease
attacks people of all races and ages. So far every one who is attacked
dies. Adult Europeans and Americans appear to be somewhat more resistant
than others on a population basis. Somewhere around sixty per cent of
them are still alive, but it's wiped out better than eighty per cent of
some groups. Children get it worse. Right now I doubt if one per cent of
the children born during the past ten years are still alive."

"It's awful!" Mary said.

"It's worse than that. It's extinction. Without kids the race will die
out." Kramer rubbed his forehead.

"Have you any ideas?"

"Children have less resistance," Kramer replied. "An adult gets exposed
to a number of diseases to which he builds an immunity. Possibly one of
these has a cross immunity against Thurston's virus."

"Then why don't you work on that line?" Mary asked.

"Just what do you think I've been doing? That idea was put out months
ago, and everyone has been taking a crack at it. There are twenty-four
laboratories working full time on that facet and God knows how many more
working part time like we are. I've screened a dozen common diseases,
including the six varieties of the common cold virus. All, incidental