ge
a wavelength?

Pouch-eyed scientists gravely consulted their periodic tables.

And how do you know when a man has been possessed? Although the enemy
was clumsy with Everset, would they continue to be clumsy? Wouldn't they
learn?

Psychologists tore their hair and bewailed the absence of an absolute
scale for humanity.

Of course, something had to be done at once. The answer, from a
technological planet, was a technological one. Build a space fleet and
equip it with some sort of a detection-fire network.

This was done in record time. The Attison Detector was developed, a
cross between radar and the electroencephalograph. Any alteration from
the typical human brain wave pattern of the occupants of a
Detector-equipped ship would boost the indicator around the dial. Even a
bad dream or a case of indigestion would jar it.

It seemed probable that any attempt to take over a human mind would
disturb something. There had to be a point of interaction, somewhere.

That was what the Attison Detector was supposed to detect. Maybe it
would.

The spaceships, three men to a ship, dotted space between Earth and
Mars, forming a gigantic sphere with Earth in the center.

Tens of thousands of men crouched behind gunfire panels, watching the
dials on the Attison Detector.

The unmoving dials.

* * * * *

"Do you think I could fire a couple of bursts?" Edwardson asked, his
fingers on the gunfire button. "Just to limber the guns?"

"Those guns don't need limbering," Cassel said, stroking his beard.
"Besides, you'd throw the whole fleet into a panic."

"Cassel," Morse said, very quietly. "Get your hand off your beard."

"Why should I?" Cassel asked.

"Because," Morse answered, almost in a whisper, "I am about to ram it
right down your fat throat."

Cassel grinned and tightened his fists. "Pleasure," he said. "I'm tired
of looking at that scar of yours." He stood up.

"Cut it," Edwardson said wearily. "Watch the birdie."

"No reason to, really," Morse said, leaning back. "There's an alarm bell
attached." But he looked at the dial.

"What if the bell doesn't work?" Edwardson asked. "What if the dial is
jammed? How would you like something cold slithering into your mind?"

"The dial'll work," Cassel said. His eyes shifted from Edwardson's face
to the motionless indicator.

"I think I'll sack in," Edwardson said.

"Stick around," Cassel said. "Play you some gin."

"All right." Edw