rst open and there stood Webber, a triumphant
Webber, face flushed, eyes wide, as he stared at the man behind the
desk.

The man smiled back and said, "Come on in, George. We've been waiting
for you."

Webber stepped through the door. "Manelli, you fool!"

There was a blinding flash as he crossed the threshold. A faint crackle
of sound reached Harry's ears; then the world blacked out....

* * * * *

It might have been minutes, or hours, or days. The man who had been
behind the desk was leaning over Harry, smiling down at him, gently
bandaging the trephine wounds at his temples.

"Gently," he said, as Harry tried to sit up. "Don't try to move. You've
been through a rough time."

Harry peered up at him. "You're--not Dr. Webber."

"No. I'm Dr. Manelli. Dr. Webber's been called away--an accident. He'll
be some time recovering. I'll be taking care of you."

Vaguely, Harry was aware that something was peculiar, something not
quite as it should be. The answer slowly dawned on him.

"The statistical analysis!" he exclaimed. "I was supposed to get some
data from Dr. Webber about an analysis, something about rising insanity
rates."

Dr. Manelli looked blank. "Insanity rates? You must be mistaken. You
were brought here for an immunity examination, nothing more. But you
can check with Dr. Webber, when he gets back."

6

George Webber sat in the little room, trembling, listening, his eyes
wide in the thick, misty darkness. He knew it would be a matter of time
now. He couldn't run much farther. He hadn't seen them, true. Oh, they
had been very clever, but they thought they were dealing with a fool,
and they weren't. He _knew_ they'd been following him; he'd known it for
a long time now.

It was just as he had been telling the man downstairs the night before:
they were everywhere--your neighbor upstairs, the butcher on the corner,
your own son or daughter, maybe even the man you were talking
to--_everywhere_!

And of course he had to warn as many people as he possibly could before
_they_ caught him, throttled him off, as they had threatened to if he
talked to anyone.

If only the people would _listen_ to him when he told them how cleverly
it was all planned, how it would only be a matter of months, maybe only
weeks or days before the change would happen, and the world would be
quietly, silently taken over by the _other_ people, the different people
who could walk through wal