fools were firing at him, up there in the
air, while you were still with him in the apartment. That's an angle
on this psi factor stuff we hadn't expected."

The voice stopped for a moment. Then it picked up again. "Drat it! I
wish you hadn't called the F. B. I. on him--they got rattled when he
came out looking like a saint in a halo and jumped fifty feet up to
float around. Some fool started shooting, and the rest joined in."

"I had to--he was talking about alien monsters. I thought he was going
crazy, Dan. I couldn't tell him anything--I promised him I wouldn't,
and I kept my promise. But I thought enough of them might catch him,
somehow.... Dan, can't we find him now? He needs us!"

* * * * *

Hawkes lay frozen. He tried to move forward, but his body was tensed,
waiting for more. If something happened now....

"Alien monsters?" Dan's voice grew bitter. "It is alien--and a
monster. This psi factor...."

The words blurred, and seemed to echo and re-echo inside Hawkes' head.
That made twice he'd heard them mention the psi factor--the strange
ability a few human minds had to perform seeming miracles. Men who had
it could make dice roll the way they wanted. Young girls sometimes
had it before puberty, and could throw heavy objects around a room
without touching them; they did not even know they were the cause of
the motion, but blamed it on poltergeists. Other men caused strange
accidents--fires, for instance--the old salamander legend!

There'd been a piece of paper--psi equals alpha, the psi factor was
the beginning of infinity for mankind. But it had been wrong. He'd
changed that, on the other side. It should have read psi equals omega,
the absolute end.

He gasped hoarsely, and heard their startled voices stop, while the
flashlight beam swung around, to pick him out in the darkness. He felt
Ellen and her younger brother, Dan, pulling him forward into the
little cave with them, and he heard their voices questioning him. But
his head was spinning madly under the sudden flood of memories that
the missing key word had suddenly brought back.

The letter from Professor Meinzer had been about his paper on
poltergeists which the old man had seen before publication. He'd been
doing research on the psi factor for the government, and he needed a
mathematician--even one who proved something which he knew wasn't
true, provided the mathematics could handle his theories.

Hawkes' head was