hts burned in them. It was not wise for anybody to burn lights
that could be seen outside their dwellings. There were police, to be
sure. But they were all in Government Center, marshaled there to try
to hold a perimeter formed by bricked-up apartment buildings. But most
of the city was dark and terribly empty save for mobs of all sizes but
all raging. Nine-tenths of the city was at the mercy of the paras.
Families darkened their homes and, terrified, hid in corners and in
closets, listening for outcries or the thunderous tramping of madmen
at their doors.

In the Med Ship the loud-speaker went on:

"_I have told you,_" said the rounded tones of the Planetary
President--but his voice shook, "_I have told you that Dr. Lett has
perfected and is making a vaccine which will protect every citizen and
cure every para. You must believe me, my fellow-citizens. You must
believe me! To paras, I promise that their fellows who were not
afflicted with the same condition will forget! I promise that no one
will remember what... what has been done in delirium! What has taken
place--and there have been tragedies--will be blotted out. Only be
patient now! Only...._"

* * * * *

Calhoun went over his glass slides again while the computer stood
motionless, apparently without life. But he had called for it to find,
in its memory banks, an organic compound of such-and-such a
crystalline form, such-and-such a diffusion rate, such-and-such a
specific gravity, and such-an-such a refractive index. Men no longer
considered that there was any effective limit to the number of organic
compounds that were possible. The old guess at half a million
different substances was long exceeded. It took time even for a
computer to search all its microfilmed memories for a compound such as
Calhoun had described.

He paced restlessly while the computer consulted its memory with faint
whirrings of cooling blowers, and occasional chucklings as memory
cubes full of exceedingly complex stereomolecules of recorded
information were searched.

"Maybe," Calhoun said, "this isn't so much a new disease as a
modification of a very old one. The very ancient Hate Disease--for the
most important symptom of this particular malady is the hate it's
stirred up. I've seen a number of sick planets--but the hate index on
this one earns it a record score." He paused for a moment as the
computer did an extra-special burping chuckle, and slipped i