er, and
another sentry.

"Tight security," said Calhoun.

"They know me," said the Minister heavily, "but they are checking my
certificate that as of morning I wasn't a para."

"I've seen quarantines before," said Calhoun, "but never one like
this! Not against disease!"

"It isn't against disease," said the Minister, thinly. "It's against
Something intelligent ... from the jungle ... who chooses victims by
reason for its own purposes."

Calhoun said very carefully:

"I won't deny more than the jungle."

Here the Minister for Health rapped on a door and ushered Calhoun
through it. They entered a huge room filled with the complex of desks,
cameras, and observing and recording instruments that the study of a
living organism requires. The setup for study of dead things is quite
different. Here, halfway down the room's length, there was a massive
sheet of glass that divided the apartment into two. On the far side of
the glass there was, obviously, an aseptic environment room now being
used as an isolation chamber.

A man paced up and down beyond the glass. Calhoun knew he must be a
para because he was cut off in idea and in fact from normal humanity.
The air supplied to him could be heated almost white-hot and then
chilled before being introduced into the aseptic chamber for him to
breath, if such a thing was desired. Or the air removed could be made
incandescent so no possible germ or its spores could get out. Wastes
removed would be destroyed by passage through a carbon arc after
innumerable previous sterilizing processes. In such rooms, centuries
before, plants had been grown from antiseptic-soaked seeds and chicks
hatched from germ-free eggs, and even small animals delivered by
aseptic Caesarean section to live in an environment in which there was
no living microorganism. From rooms like this men had first learned
that some types of bacteria outside the human body were essential to
human health. But this man was not a volunteer for such research.

He paced up and down, his hands clenching and unclenching. When
Calhoun and the Minister for Health entered the outer room, he glared
at them. He cursed them, though inaudibly because of the sheet of
glass. He hated them hideously because they were not as he was;
because they were not imprisoned behind thick glass walls through
which his every action and almost his every thought could be watched.
But there was more to his hatred than that. In the midst of fury so
g